Base station apparatus and communication control method

ABSTRACT

A disclosed base station apparatus is capable of communicating with a user equipment terminal using a downlink shared channel. The base station apparatus includes a selection unit selecting a user equipment terminal transmitting a shared channel from among user equipment terminals other than a user equipment terminal in which a time frame to transmit the shared channel or a time frame to receive acknowledgement information with respect to the shared channel overlaps with a time interval when cells are measured, the cells operating at a different frequency, a user equipment terminal in sleep mode of discontinuous reception mode, a user equipment terminal that has not received radio quality information, and a user equipment terminal having no data to be transmitted and a transmission unit transmitting the shared channel to the user equipment terminal selected by the selection unit.

TECHNICAL FIELD

The present invention generally relates to a mobile communication systememploying an Orthogonal Frequency Division Multiplexing (OFDM) scheme,and more particularly to a base station apparatus and a communicationcontrol method to be used in the same system.

BACKGROUND ART

As a next-generation system of the W-CDMA (Wideband Code DivisionMultiple Access) and the HSDPA (High Speed Downlink Packet Access), anLTE system has been studied by 3GPP (3^(rd) Generation PartnershipProject) which is a standards body of the W-CDMA. In the LTE system as aradio access system, an OFDM (Orthogonal Frequency DivisionMultiplexing) scheme and an SC-FDMA (Single-Carrier Frequency DivisionMultiple Access) scheme have been studied to be applied to the downlinkcommunications system and the uplink communications system, respectively(see, for example, Non Patent Document 1).

In the OFDM scheme, a frequency band is divided into plural sub-carriershaving narrower frequency bands, and data are transmitted on each subsub-carrier and the sub-carriers are closely arranged so as not tointerfere with each other, so that fast data transmission can beachieved and an efficiency use of the frequency band can be improved.

In the SC-FDMA scheme, a frequency band is divided in a manner so thatdifferent frequencies can be separately used among plural terminals(user equipment terminals) and as a result, interferences betweenterminals can be reduced. Further, in the SC-FDMA scheme, a range oftransmission power fluctuation can be made smaller; therefore lowerenergy consumption of terminals can be achieved and a wider coveragearea can be obtained.

The LTE system is a communication system using shared channels in bothdownlink and uplink. For example, in downlink, a base station apparatusselects a mobile station (user equipment terminal) to communicate usingthe shared channel with respect to each sub-frame (each 1 ms) andtransmits the shared channel to the selected mobile station. In thiscase, a process of selecting the mobile station to communicate asdescribed above is called a scheduling process.

Further, in the LTE system, so-called Adaptive Modulation and Coding(AMC) is applied; therefore, transmission formats of the shared channelsmay vary among different sub-frames. Herein, the transmission formatincludes various information items indicating such as allocationinformation of the resource blocks which are frequency resources,modulation scheme, payload size, HARQ (Hybrid Automatic Repeat reQuest)information such as a Redundancy version parameter, a process number andthe like, the number of streams, and a Pre-coding vector.

In the LTE system, identification information identifying the mobilestation that communicates by using the shared channel in the sub-frameand the transmission format of the downlink shared channel are reportedusing Downlink Scheduling Information to be mapped to a PhysicalDownlink Control Channel (PDCCH). The Physical Downlink Control Channel(PDCCH) may also be called a DL L1/L2 Control Channel.

-   Non Patent Document 1: 3GPP TR 25.814 (V7.0.0), “Physical layer    Aspects for Evolved UTRA,” June 2006

DISCLOSURE OF INVENTION Problems to be Solved by the Invention

When the scheduling process or a process of determining the transmissionformat is not adequately controlled, the transmission characteristics orradio capacity of the system may be impaired.

Further, all the user equipment terminals being connected are treated astargets of the scheduling; therefore, effective scheduling may not befeasible.

The present invention is made in light of the problems and may provide abase station apparatus and a communication control method capable of, inLTE downlink, adequately performing the scheduling process and thedetermination process of the transmission formats in the AMC (AdaptiveModulation and Coding) scheme.

Means for Solving the Problems

According to an aspect of the present invention, there is provided abase station apparatus capable of communicating with a user equipmentterminal using a downlink shared channel. The base station apparatusincludes

a selection unit selecting a user equipment terminal transmitting ashared channel from among user equipment terminals other than:

a user equipment terminal in which a time frame to transmit the sharedchannel or a time frame to receive acknowledgement information withrespect to the shared channel overlaps with a time interval when cellsare measured, the cell operating at a different frequency,

a user equipment terminal in sleep mode of discontinuous reception mode,

a user equipment terminal that has not received radio qualityinformation, and

a user equipment terminal having no data to be transmitted; and

a transmission unit transmitting the shared channel to the userequipment terminal selected by the selection unit.

According to another aspect of the present invention, there is provideda base station apparatus capable of communicating with a user equipmentterminal using a downlink shared channel. The base station apparatusincludes

a selection unit selecting a user equipment terminal transmitting ashared channel from among user equipment terminals other than a userequipment terminal in which a time frame to transmit the shared channelor a time frame to receive acknowledgement information with respect tothe shared channel overlaps with a time interval when cells aremeasured, the cell operating at a different frequency; and

a transmission unit transmitting the shared channel to the userequipment terminal selected by the selection unit.

According to another aspect of the present invention, there is provideda base station apparatus capable of communicating with a user equipmentterminal using uplink and downlink shared channels. The base stationapparatus includes

a selection unit selecting a user equipment terminal transmitting ashared channel from among user equipment terminals other than:

a user equipment terminal in which a time frame to transmit the downlinkshared channel overlaps with a time frame to transmit the uplink sharedchannel,

a user equipment terminal in which the time frame to transmit thedownlink shared channel overlaps with a time frame to transmit, inuplink, to a sounding reference signal, downlink radio qualityinformation, a scheduling request signal, or a random access channel,

a user equipment terminal in which the time frame to transmit thedownlink shared channel overlaps with a time frame to transmitacknowledgement information (ACK/NACK) with respect to the downlinkshared channel,

a user equipment terminal in which the time frame to transmitacknowledgement information with respect to the downlink shared channeloverlaps with a time frame to transmit a downlink common channel,

a user equipment terminal in which the time frame to transmitacknowledgement information with respect to the downlink shared channeloverlaps with a time frame to transmit acknowledgement information withrespect to an uplink shared channel, and

a user equipment terminal in which the time frame to transmitacknowledgement information with respect to the downlink shared channeloverlaps with a time frame to transmit control information for downlinkor uplink Persistent Scheduling; and

a transmission unit transmitting the downlink shared channel to the userequipment terminal selected by the selection unit.

According to another aspect of the present invention, there is provideda communication control method for a base station apparatus capable ofcommunicating with a user equipment terminal using a downlink sharedchannel. The method includes

a first excluding step of excluding a first user equipment terminal fromcandidate user equipment terminals transmitting a shared channel, in thefirst user equipment terminal a time frame to transmit the sharedchannel or a time frame to receive acknowledgement information withrespect to the shared channel overlapping with a time interval whencells are measured, the cell operating at a different frequency;

a second excluding step of excluding a second user equipment terminalfrom candidate user equipment terminals transmitting a shared channel,the second user equipment terminal being in sleep mode of discontinuousreception mode;

a third excluding step of excluding a third user equipment terminal fromcandidate user equipment terminals transmitting a shared channel, thethird user equipment terminal not having received radio qualityinformation;

a fourth excluding step of excluding a fourth user equipment terminalfrom candidate user equipment terminals transmitting a shared channel,the fourth user equipment terminal having no data to be transmitted;

a selection step of selecting a user equipment terminal transmitting ashared channel; and

a transmitting step of transmitting a shared channel to the userequipment terminal selected in the selection step.

Advantageous Effect of the Invention

According to an embodiment of the present invention, there may beprovided a base station apparatus and a communication control methodcapable of, in LTE downlink, adequately performing the schedulingprocess and the determination process of the transmission formats in theAMC.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing a configuration of a radiocommunication system according to an embodiment of the presentinvention;

FIG. 2 is a flowchart showing a process of a DL MAC data transmissionaccording to an embodiment of the present invention;

FIG. 3 is a flowchart showing process of scheduling coefficientcalculation and candidate UE selection according to an embodiment of thepresent invention;

FIG. 4 is a flowchart showing a process of control for a TFR selectionaccording to an embodiment of the present invention;

FIG. 5 is a drawing showing resource blocks allocated to asynchronization signal and a broadcast channel;

FIG. 6 shows a DL TF Related Table;

FIG. 7 is a partial block diagram of a base station apparatus accordingto an embodiment of the present invention;

FIG. 8 is a partial block diagram of a user equipment terminal accordingto an embodiment of the present invention;

FIG. 9 is a flowchart showing a process of a DL MAC data transmissionaccording to an embodiment of the present invention;

FIG. 10 is a flowchart showing a process of scheduling coefficientcalculation and candidate UE selection according to an embodiment of thepresent invention;

FIG. 11 is a flowchart showing a process of control for a TFR selectionaccording to an embodiment of the present invention;

FIG. 12 is a flowchart showing a control process of allocating resourceblock groups according to an embodiment of the present invention;

FIG. 13 is a partial block diagram of a base station apparatus accordingto an embodiment of the present invention;

FIG. 14 is a drawing showing an interference in a user equipmentterminal; and

FIG. 15 is a drawing showing a method of reducing the interference of anuplink transmission signal to a downlink reception signal.

EXPLANATION OF REFERENCES

-   -   100 ₁, 100 ₂, 100 ₃, 100 _(n): USER EQUIPMENT TERMINAL(S)    -   104: AMPLIFIER    -   106: TRANSMISSION/RECEIVING SECTION    -   108: BASEBAND SIGNAL PROCESSING SECTION    -   110: APPLICATION SECTION    -   200: BASE STATION APPARATUS    -   202: MBMS SUBFRAME DETECTION SECTION    -   204: PCH RACH RESPONSE DETECTION SECTION    -   206: SCHEDULING COEFFICIENT CALCULATION SECTION    -   208: MULTIPLEXED UE NUMBER COUNTING SECTION    -   210: TRANSPORT FORMAT/RESOURCE BLOCK SELECTION SECTION    -   252: LAYER 1 PROCESSING SECTION    -   254: USER EQUIPMENT STATUS MANAGEMENT SECTION    -   256: SCHEDULING COEFFICIENT CALCULATION SECTION    -   258: UE SELECTION SECTION    -   260: MAC CONTROL SIGNAL GENERATION SECTION    -   262: COMMON CH/MCH RESOURCE MANAGEMENT SECTION    -   264: FREQUENCY RESOURCE MANAGEMENT SECTION    -   266: PERSISTENT RESOURCE MANAGEMENT SECTION    -   268: TFR SELECTION SECTION    -   270 (270 ₁, 270 ₂, . . . , 270 _(n)): HARQ CONTROL SECTION    -   272: RLC/PDCP PROCESSING SECTION    -   2721 _(n,k): RLC BUF    -   300: ACCESS GATEWAY APPARATUS    -   400: CORE NETWORK

BEST MODE FOR CARRYING OUT THE INVENTION

Next, a best mode for carrying out the present invention is describedbased on the embodiments described below with reference to theaccompanying drawings.

Throughout the figures for illustrating the embodiments of the presentinvention, the same reference numerals are used for the same orequivalent elements and the repeated descriptions thereof may beomitted.

First, a radio communication system having a base station apparatusaccording to an embodiment of the present invention is described withreference to FIG. 1.

First Embodiment

As shown in FIG. 1, the radio communication system 1000, which may be anEvolved UTRA (Universal Terrestrial Radio Access) and UTRAN (UTRANetwork) system (a.k.a an LTE (Long Term Evolution) system or a super 3Gsystem), includes a base station apparatus (eNB: eNode B) 200 and pluraluser equipment (UE) 100 (100 ₁, 100 ₂, 100 ₃, . . . 100 _(n); n: aninteger greater than zero (0)) (hereinafter, the user equipment (UE) maybe referred to as a user equipment terminal(s)). The base stationapparatus 200 is connected to an upper node station such as an accessgateway apparatus 300. The access gateway apparatus 300 is connected toa core network 400. In this case, the user equipment (UE) terminals 100_(n) are in communication with the base station apparatus 200 in a cell50 based on the Evolved UTRA and UTRAN radio communication scheme.

Each of the user equipment terminals (100 ₁, 100 ₂, 100 ₃, . . . 100_(n)) has the same configuration, functions, and status. Therefore,unless otherwise described, the term user equipment (UE) 100 _(n) may becollectively used in the following descriptions.

As the radio access scheme in the radio communication system 1000, theOFDM (Orthogonal Frequency Division Multiplexing) scheme and the SC-FDMA(Single-Carrier Frequency Division Multiplexing Access) scheme are usedin downlink and uplink communications, respectively. As described above,the OFDM scheme is a multi-carrier transmission scheme in which afrequency band is divided into plural sub-carriers having narrowfrequency bands and data are mapped on each sub-carrier to betransmitted. The SC-FDMA scheme is a single-carrier transmission schemein which a frequency band is divided so that different frequencies canbe used among plural terminals and as a result, interferences betweenterminals can be reduced.

Next, communication channels used in the Evolved UTRA and UTRAN radiocommunication scheme are described.

In downlink communications, a Physical Downlink Shared Channel (PDSCH)that is shared among the user equipment terminals 100 _(n) and aPhysical Downlink Control Channel (PDCCH) are used. In downlink, userinformation and transport format information of a Downlink SharedChannel, the user information and the transport information of an UplinkShared Channel, acknowledgement information of the Uplink Shared Channeland the like are reported via the Physical Downlink Control Channel(PDCCH). User data are transmitted via the Physical Downlink SharedChannel (PDSCH). The user data are transmitted via a Downlink SharedChannel (DL-SCH) as a transport channel.

In uplink communication, a Physical Uplink Shared Channel (PUSCH) thatis shared among user equipment terminals 100 _(n) and an LTE controlchannel are used. The LTE control channel has two types, one is to betime-domain multiplexed with the Physical Uplink Shared Channel (PUSCH)and the other is to be frequency-domain multiplexed with the PhysicalUplink Shared Channel (PUSCH). The control channel to befrequency-domain multiplexed with the Physical Uplink Shared Channel(PUSCH) is called a Physical Uplink Control Channel (PUCCH).

In uplink communication, a downlink Channel Quality Indicator (CQI) tobe used for scheduling in downlink and an Adaptive Modulation and Coding(AMC) and acknowledgement information of the Downlink Shared Channel(HARQ (Hybrid Automatic Repeat reQuest) ACK information) are transmittedvia the LTE control channel. Further, the user data are transmitted viathe Physical Uplink Shared Channel (PUSCH). The user data aretransmitted via an Uplink Shared Channel (UL-SCH) as a transportchannel.

Next, a Downlink MAC (DL MAC) data transmission procedure as acommunication control method performed in a base station apparatusaccording an embodiment of the present invention is described.

In this embodiment, a logical channel corresponds to, for example, aRadio bearer; and a Priority class corresponds to, for example, apriority level.

Next, an allocation unit of the transmission bandwidth of the PhysicalDownlink Shared Channel (PDSCH) is described. The allocation of thePhysical Downlink Shared Channel (PDSCH) is performed with respect toeach sub-frame by treating, for example, a Resource block group(hereinafter may be referred to as RB group) as a unit, the RB groupbeing defined as a system parameter. Each RB group includes pluralResource Blocks (RBs), and a corresponding relationship between the RBsand the RB group is set as a system parameter via an external inputinterface (I/F). The allocation of the transmission bandwidth bytreating the RB group as a unit is also performed on the PhysicalDownlink Shared Channel (PDSCH) to which Persistent scheduling isapplied. In the following, a case is described where the RB group isconfigured. However, without configuring the RB block, the allocation ofthe Physical Downlink Shared Channel (PDSCH) may be performed bytreating the resource block as a unit.

Further, in the descriptions below, a dynamic scheduling corresponds toa first resource allocation method of dynamically allocating radioresources. When the dynamic scheduling is applied to the Downlink SharedChannel (DL-SCH), radio resources are allocated to arbitrary sub-frameswith respect to the user equipment (UE). Further, in this case, variousvalues may be set as the values of the transmission format including theallocation information of the resource blocks as frequency resources,modulation scheme, payload size, HARQ information items, such as aRedundancy version parameter, a process number and the like, andinformation items of an MIMO and the like.

On the other hand, the Persistent scheduling is a scheduling method ofallocating transmission opportunities at a predetermined cycle inaccordance with a type of data or features of the application totransmit/receive data and corresponds to a second resource allocationmethod of allocating radio resources at the predetermined cycle. Namelywhen the Persistent scheduling is applied to the Downlink Shared Channel(DL-SCH), the Downlink Shared Channel (DL-SCH) is transmitted usingpredetermined sub-frames with respect to the user equipment (UE).Further, in this case, predetermined values are set as the values of thetransmission format including the allocation information of the resourceblocks as frequency resources, modulation scheme, payload size, HARQinformation items, such as the Redundancy version parameter, the processnumber and the like, and the information items of the MIMO and the like.Namely, the shared channel (radio resource) is allocated to thepredetermined sub-frames, and the Downlink Shared Channel (DL-SCH) istransmitted using the predetermined transmission format. In this case,the predetermined sub-frames may be arranged, for example, at apredetermined cycle. Further, the predetermined transmission format isnot necessarily fixed to one type, and so, plural types of transmissionformats may be provided.

Next, a downlink MAC data transmission procedure is described withreference to FIG. 2. FIG. 2 shows a procedure, starting from ascheduling process performed by calculating scheduling coefficients, toa DL TFR selection process of determining the transport format and theRB group to be allocated.

As shown in FIG. 2, in step S202, a DL MAC maximum multiplexing numberN_(DLMAX) is set in the base station apparatus 200. The DL MAC maximummultiplexing number N_(DLMAX) is the maximum multiplexing number in onesub-frame of the Downlink Shared Channel (DL-SCH) to which the DynamicScheduling is applied and is designated via the external input interface(I/F).

Next, in step S206, the base station apparatus 200 counts a PCH (PagingChannel) number and an RACH (Random Access Channel) response number inthe sub-frame and defines the numbers as N_(PCH) and N_(RACHres),respectively. In this case, instead of using actual PCH number and RACHresponse number, the number of Downlink Scheduling Information for thePCH and the number of Downlink Scheduling Information for the RACHresponse may be calculated as the PCH number and the RACH responsenumber, respectively.

Next, in step S208, calculation of scheduling coefficients is performedin the base station apparatus 200. The user equipment (UE) terminals inwhich radio resources are allocated based on the Dynamic scheduling inthe sub-frame are selected. The number of user equipment (UE) terminalsin which the radio resources are allocated based on the Dynamicscheduling in the sub-frame is defined as N_(DL-SCH).

In step S212, a Downlink Transport format and Resource selection (DLTFR) is performed. Namely transmission formats are determined and theradio resources area allocated with respect to each of a Synchronizationsignal (also called a Synchronization Channel (SCH)), a BroadcastChannel (BCH), a Paging Channel (PCH), a Random Access Channel (RACH)response (RACH response, or message2 in random access procedure), theDownlink Shared Channel (DL-SCH) to which the Persistent Scheduling isapplied, and the Downlink Shared Channel (DL-SCH) to which the DynamicScheduling is applied.

Next, the Calculation for Scheduling coefficients performed in step S208is described with reference to FIG. 3.

FIG. 3 shows a process of selecting the user equipment (UE) terminal(s)in which radio resources are allocated based on the Dynamic schedulingby calculating the Scheduling coefficients. The base station apparatus200 performs the following processes with respect to all the userequipment (UE) terminals in an LTE active state including, for example,in an RRC (Radio Resource Control) connecting state.

As shown in FIG. 3, in step S302, formulas of n=1 and N_(scheduling)=0are provided; where n denotes an index of the user equipment terminals100 _(n) and n=1, . . . , N (N is an integer greater than 0).

Next, in step S304, Renewal of HARQ (Hybrid Automatic Repeat reQuest)Entity Status is performed. In this step, in the user equipment (UE), aprocess receiving ACK as the acknowledgement information with respect tothe Downlink Shared Channel (DL-SCH) is released. Further, a process inwhich the maximum number of retransmissions has been reached is alsoreleased and the user data in the process are discarded. The maximumnumber of retransmissions is set with respect to each Priority class viathe external input interface (I/F). Further, it is assumed that themaximum number of retransmissions of MAC PDU (Protocol Data Unit), withwhich plural logical channels are multiplexed, complies with the maximumnumber of retransmissions of a logical channel having the highestPriority Class.

Next, in step S306, a Measurement Gap Check is performed. Morespecifically, it is determined whether the sub-frame (i.e., thesub-frame transmitting the Downlink Shared Channel (DL-SCH)) is includedin the Measurement Gap or whether the sub-frame receiving theacknowledgement information (ACK/NACK) with respect to the DownlinkShared Channel (DL-SCH) is included in the Measurement Gap. Whendetermining that the sub-frame is included in the Measurement Gap orthat the sub-frame receiving the acknowledgement information (ACK/NACK)is included in the Measurement Gap, an NG (signal) is returned,otherwise, an OK (signal) is returned. The Measurement Gap refers to atime interval when cells operating at a different frequency are measuredfor a different-frequency handover of the user equipment (UE), andduring the time interval, communications cannot be performed andtherefore, the user equipment (UE) cannot receive the Downlink SharedChannel (DL-SCH). Further, during the time period when measuring thecells operating at a different frequency, the user equipment (UE) cannottransmit the acknowledgement information (ACK/NACK). As a result, thebase station apparatus 200 cannot receive the acknowledgementinformation (ACK/NACK). Accordingly, when a result of the MeasurementGap Check is NG (NG in step S306), the user equipment (UE) terminal isexcluded from a target of the scheduling process.

In this case, the cell operating at a different frequency may be a cellof the Evolved UTRA and UTRAN system or a cell of another system suchas, for example, GSM, WCDMA, TDD-CDMA, CDMA 2000, or WiMAX system.

Next, in step S308, a discontinuous reception (DRX) is checked. Namelyit is determined whether the user equipment (UE) is in DRX(Discontinuous Reception) mode. When determining that the user equipment(UE) is in DRX mode, it is further determined whether the sub-frame isincluded in a DRX reception timing. When determining that the userequipment (UE) is in DRX (Discontinuous Reception) mode and thesub-frame is not included in the DRX reception timing, the “NG” isreturned, otherwise the “OK” is returned. Namely when determining thatthe user equipment (UE) is not in DRX mode or that the user equipment(UE) is in DRX mode and the sub-frame is included in the DRX receptiontiming, the OK is returned. Further, in a case of not being in DRX mode,a value of flag described below is set to 0 (zero); and in a case ofbeing in DRX mode and in DRX reception timing, the value of flag_(DRX)is set to 1 (one). Herein, the DRX reception timing refers to a timingwhen data can be received during in DRX mode. Further, when a state isin DRX mode and not in the DRX reception timing, the state correspondsto a sleep mode.

When a result of the DRX check is NG (NG in step S308), the userequipment is excluded from a target of the scheduling process.

Next, in step S310, an Uplink Synchronization Check (UL Sync Check) isperformed. More specifically, it is determined whether the uplinksynchronization state of the user equipment (UE) is classified as“Synchronization loss Type B”. When determining that the uplinksynchronization state is Synchronization loss Type B, the NG isreturned, and when determining that the uplink synchronization state isnot Synchronization loss Type B, the OK is returned.

When a result of the UL Sync Check is NG (NG in step S310), the userequipment is excluded from a target of the scheduling process. Further,when the uplink synchronization state of the user equipment (UE) isclassified as “Synchronization loss Type A”, the user equipment is notexcluded from a target of the scheduling process.

The base station apparatus (eNB) 200 performs the following two kinds ofdetections (determinations) for the uplink synchronization state withrespect to all the user equipment terminals 100 _(n) in RRC_connectedstate.

First, the base station apparatus (eNB) 200 performs Power detection ofa Sounding RS (Reference signal) of the user equipment (UE) within arange of Window 1 determined by taking the cell radius intoconsideration and having a similar size of a Window to wait for a RACHpreamble. Namely when a metric used in the Power detection of the userequipment exceeds a predetermined threshold value, it is determined asPower detection OK, otherwise, it is determined as Power detection NG.Further, a reflection time (which is a time period required to determineOK or NG) in this detection is typically in a range from 200 ms to 1,000ms in a state while the Sounding RS is continuously received.

Second, the base station apparatus (eNB) 200 performs FFT timingdetection to detect whether a signal of the user equipment (UE) isincluded within a range of Window 2 defined based on an FFT timing and aCP (Cyclic Prefix) length. Therefore, when the signal of the userequipment (UE) is included in the Window 2, it is determined as FFTtiming detection OK, and when there is no main path of the userequipment (UE), it is determined as FFT timing detection NG. Further,the reflection time (which is a time period required to determine OK orNG) in this detection is typically in a range from 1 ms to 200 ms in astate while the Sounding RS is continuously received.

The “Synchronization loss Type A” refers to a Synchronization state ofthe user equipment (UE) in which the result of Power detection isdetermined as OK and the result of FFT timing detection is determined asNG. On the other hand, the “Synchronization loss Type B” refers to aSynchronization state of the user equipment (UE) in which the result ofPower detection is determined as NG and the result of FFT timingdetection is determined as NG.

Next, in step S312, a Received CQI (Channel Quality Indicator) Check isperformed. More specifically, the base station apparatus (eNB) 200determines whether CQI across the system bandwidth is received from theuser equipment (UE). In a case where the CQI across the system bandwidthis received in the sub-frame or in a sub-frame preceding the sub-frameand the CQI across the system bandwidth is determined as OK at least onetime according to a CQI reliability determination result, the OK isreturned, otherwise, the NG is returned. The CQI reliabilitydetermination may be performed by, for example, calculating an SIR(Signal-interference Ratio) of the received signal of the CQI anddetermining the reliability of the CQI based on the calculated SIR. Inthis case, for example, when the SIR is less than a predeterminedthreshold value, the reliability of the CQI is determined as NG, andwhen the SIR is equal to or greater than the predetermined thresholdvalue, the reliability of the CQI is determined as OK.

When a result of the Received CQI Check is NG (NG in step S312), theuser equipment is excluded from a target of the scheduling process.Further, in a case where the result of the Received CQI Check is NG,even when the user equipment (UE) has a logical channel to whichPersistent Scheduling is applied, the user equipment is excluded from atarget of the scheduling process. Further, in this case, when aPersistent Resource allocated to the user equipment (UE) is included(allocated) in the sub-frame, the Persistent Resource is released.Herein, the Persistent Resource refers to a Resource block reserved forthe Persistent Scheduling.

Next, in step S314, a Persistent Scheduling Check is performed. ThePersistent scheduling is a scheduling method of allocating transmissionopportunities at a predetermined cycle in accordance with a type of dataor features of the application to transmit/receive data. Further, thetype of data may include data of Voice Over IP, Streaming data or thelike. The Voice Over IP and the Streaming data correspond to theapplications.

In step S314, it is determined whether the user equipment (UE) has alogical channel to which Persistent Scheduling is applied. Whendetermining that the user equipment (UE) has a logical channel to whichPersistent Scheduling is applied, the process goes to step S330 in whicha Persistent scheduled Sub-frame Check is performed. Otherwise, theprocess goes to step S316 in which a Localized/Distributed Check isperformed. In localized (transmission), it may be advantageous toallocate relatively consecutive frequency blocks (resource blocks) basedon CQI because a fading frequency in a propagation environment betweenthe user equipment (UE) and the base station apparatus 200 is(relatively) small. On the other hand, in Distributed (transmission), itmay be advantageous to allocate frequency blocks (resource blocks) whichare relatively discretely distributed (separated) from each otherregardless of the CQI values because the fading frequency in apropagation environment between the user equipment (UE) and the basestation apparatus 200 is (relatively) large.

In step S330, it is determined in the sub-frame whether the Persistentresource is allocated to a logical channel to which Persistentscheduling is applied, the user equipment (UE) having the logicalchannel. When determining that the Persistent resource is allocated tothe logical channel (OK in step S330), the process goes to step S332 inwhich an Assign/Release Check is performed. When determining that thePersistent resource is not allocated to the logical channel (NG in stepS330), the process goes to step S316 in which the Localized/DistributedCheck is performed.

In step S332, it is determined whether there are transmittable data inthe logical channel of the user equipment (UE), the Persistentscheduling being applied to the logical channel. Namely the base stationapparatus 200 determines in a data buffer whether there aretransmittable data of the logical channel to which Persistent schedulingis applied. When determining that there are transmittable data (Assignin step S332), the process goes to step S334 in which a Data Size Checkis performed. On the other hand, when determining that there are notransmittable data, the process goes to step S336 in which a Persistentresource Release process is performed.

In step S334, it is determined whether a size of the transmittable dataof the logical channel of the user equipment is equal to or greater thana threshold value Threshold_(data) _(—) _(size), the Persistentscheduling being applied to the logical channel. When determining thatthe size of the transmittable data is equal to or greater than thethreshold value Threshold_(data) _(—) _(size) (NG in step S334), theprocess goes to step S336 in which the Persistent Resource Releaseprocess is performed. On the other hand, when determining that the sizeof the transmittable data is less than the threshold valueThreshold_(data) _(—) _(size) (OK in step S334), the process goes tostep S338 in which a Persistent Resource Reservation process isperformed.

In step S338, the Persistent Resource to be allocated to the logicalchannel of the user equipment (UE) is reserved, the Persist schedulingbeing applied to the logical channel. Further, the calculation of thescheduling coefficients described below is also performed with respectto the user equipment (UE) to which the Persistent Resource is appliedin the sub-frame. Further, when the radio resources are allocated to thelogical channel to which the Dynamic Scheduling is applied in thesub-frame, the logical channel to which the Persistent scheduling isapplied and the logical channel to which the Dynamic scheduling isapplied are multiplexed and the MAC PDU (DL-SCH) is transmitted.

In step S336, the Persistent Resource to be allocated to the logicalchannel of the user equipment (UE) is released, the Persistentscheduling being applied to the logical channel. In this case, it isassumed that the Persistent Resource is released with respect to thesub-frame only, and in the timing when the next Persistent Resource isallocated, the Assign/Release Check is newly performed.

In step S316, the downlink transmission type of the user equipment (UE),i.e., whether Localized (transmission) type or Distributed(transmission) type, is determined. The transmission type may beindependently controlled (managed) between Downlink communications andUplink communications.

For example, when the CQI across the system bandwidth of the userequipment (UE) is equal to or greater than a threshold value“Threshold_(CQI)” and an Fd estimation value is equal to or less than athreshold value “Threshold_(Fd,DL)”, the Localized transmission isdetermined. Otherwise, the Distributed transmission is determined.

As the Fd estimation value, a value reported in an RRC message such as aMeasurement report from the user equipment (UE) or a value calculatedbased on a time correlation value of the Sounding reference signaltransmitted from the user equipment (UE) terminal may alternatively beused.

Further, in the above example, the transmission type is determined basedon both CQI value across the system bandwidth and the Fd estimationvalue. However, alternatively, the transmission type may be determinedbased on only the CQI value across the system bandwidth or only the Fdestimation value.

Next, in step S318, a Buffer Status Check is performed. Morespecifically, with respect to the logical channel of the user equipment(UE), it is determined whether there are transmittable data in thesub-frame. Namely the base station apparatus 200 determines whetherthere are transmittable data in the data buffer with respect to eachlogical channel of the user equipment (UE). When determining that thereare no transmittable data in any of the logical channels, the NG isreturned. On the other hand, when determining that there aretransmittable data in at least one logical channel, the OK is returned.Herein, the transmittable data includes newly transmittable data orretransmittable data. The logical channels do not include any logicalchannel that the Persistent Resource is reserved in step S338. Namelywhen transmittable data is included only in the logical channel that thePersistent Resource is reserved in step S338, the NG is returned. Whenthere is only control information of an MAC layer as the transmittabledata, the control information may be treated as a logical channelbelonging to the same Priority class as a Dedicated Control Channel(DCCH) belongs. When a result of the Buffer Status Check is NG (NG instep S318), the user equipment is excluded from a target of thescheduling process. On the other hand, when a result of the BufferStatus Check is OK (OK in step S318), a logical channel having theHighest priority is selected from among the logical channels havingtransmittable data based on the following selection logics describedbelow and the process goes to step S320 in which a SchedulingCoefficient Calculation process is performed. When the logical channelhaving the Highest priority is selected, the logical channel in whichPersistent Resource is reserved in step S338 is also treated as a targetof the selection.

Selection logic 1: The logical channel having the highest priority levelis defined as the logical channel having the Highest priority.

Selection logic 2: When there are plural logical channels satisfying theSelection logic 1, the logical channel(s) having the transmittable datais defined as the logical channel(s) having the Highest priority.

Selection logic 3: In a case where there are plural logical channelssatisfying the Selection logic 2, when there is a Dedicated ControlChannel (DCCH), the Dedicated Control Channel (DCCH) is defined as thelogical channel having the Highest priority; and when there is noDedicated Control Channel (DCCH), any of the logical channels from amongthe plural logical channel is determined as the logical channel havingthe Highest priority.

When those selection logics are applied, not the retransmission data ofthe logical channel having a lower priority but the new data of thelogical channel having a higher priority are more likely to bedetermined as the data of the logical channel having higher priority.

The above-described process that the user equipment (UE) terminal isexcluded from a target of the scheduling process in steps S306, S308,S310, S312, and S318 means that the Scheduling Coefficient Calculationprocess described below is not to be performed. As a result, in thesub-frame, a Downlink Shared Channel (DSCH) is not transmitted to theuser equipment (UE) terminal. In other words, the base station apparatus200 performs the scheduling with respect to the user equipment (UE)terminals other than the user equipment (UE) terminals determined to beexcluded from the targets of the scheduling in the above steps S306,S308, S310, S312, or S318; namely the base station apparatus 200 selectsuser equipment (UE) terminals to which the shared channel is to betransmitted and transmits downlink shared channel (DL-SCH) to theselected user equipment (UE) terminals.

In step S320, with respect to the logical channel determined as thelogical channel having the Highest priority in step S318, the Schedulingcoefficients are calculated based on an evaluation formula describedbelow.

Tables 1 and 2 show parameters set via the external input interface(I/F).

TABLE 1 Set with respect No Parameter name to each Remarks 1 A_(pc)Priority This is a Priority Class Priority level class coefficient basedon Priority Class. Priority Class refers to an index or class indicatinga priority level of data defined with respect to each logical channel. 2B(flag_(HO)) UE This is a HO (HandOver) priority level coefficient givento transmit remaining data of UE performing Inter-eNB HO. In thesub-frame, this value is set based on a value of flag “flag_(HO)”related to the UE. When flag_(HO) = 0, B(0) is set to a fixed value 1.0(B(0) = 1.0), and only when flag_(HO) = 1, this value is set viaexternal input interface (I/F). For example, when flag_(HO) = 1, bysetting B(flag_(HO)) to 2.0 (B(flag_(HO)) = 2.0), it becomes possible topreferentially transmit remaining data of UE performing Inter-eNB HO.For example, when communicating between the UE and base stationapparatus 200 about the control for the Inter eNB HO(HandOver),flag_(HO) may be set to 1 (flag_(HO) = 1), otherwise, flag_(HO) may beset to 0 (flag_(HO) = 0). 3 D(flag_(DRX)) UE This is a DRX prioritylevel coefficient given to preferentially transmit data of UE in DRXmode and DRX reception timing. In the sub-frame, this value is set basedon a value of flag “flag_(DRX)” related to the UE. When flag_(DRX) = 0,D(0) is set to a fixed value 1.0 (D(0) = 1.0), and only when flag_(DRX)= 1, this value is set via external input interface (I/F). For example,when flag_(DRX) = 1, by setting D(flag_(DRX)) to 2.0 (D(flag_(DRX)) =2.0), it becomes possible to preferentially transmit data of UE in DRXmode and DRX reception timing.. It is assumed that in DRX mode and DRXreception timing, flag_(DRX) is set to 1(flag_(DRX) = 1), otherwise,flag_(DRX) is set to 0 (flag_(DRX) = 0). 4 E_(PC)(Num_(retex)) PriorityThis is a retransmission priority coefficient class used topreferentially transmit data to UE having a large number ofretransmission of HARQ. When there are plurality of Processes havingretransmission data, a value of the largest number of the retransmissionis defined as Num_(retx). Depending on the value of the number ofretransmission times, the setting value of E_(PC)(Num_(retex)) is set asdescribed above via the external input interface (I/F). For example, asshown in the table below By increasing the value of E_(PC)(Num_(retex))as the value of Num_(retx). increases, it becomes possible topreferentially transmit data to UE having a large number ofretransmission of HARQ. Numretx setting value of EPC(Numretex) 0 1.0 11.2 2, 3 1.8 4-16 2.5 5 H(flag_(gap) _(—) _(control)) UE This is a gapcontrol priority level coefficient used to preferentially transmit datato UE in which a Measurement gap control mode is ON to measure cellsoperating at a different frequency. In the sub-frame, this value is setbased on a value of flag_(gap) _(—) _(control) of UE. When flag_(gap)_(—) _(control) = 0, H(0) is set to a fixed value 1.0 (H(0) = 1.0), andonly when flag_(DRX) = 1, this value is set via external input interface(I/F). When UE is in Measurement gap control mode (i., e., whenMeasurement gap control mode is ON), flag_(DRX) is defined as 1(flag_(DRX) = 1), otherwise flag_(DRX) is defined as 0 (flag_(DRX) = 0).For example, to increase the priority level of UE where Measurement gapcontrol mode is ON, H(1) may be set 10 (H(1) = 10).

TABLE 2 Set with respect No Parameter name to each Remarks 6F_(PC)(t_(RLC) _(—) _(buffered)) Priority This is a residence timepriority level class coefficient used to preferentially transmit data toUE in which buffer residence time of RLC is long. The buffer residencetime of RLC SDU related to a logical channel having the Highest priorityis used as an argument. The definition of buffer residence time of RLCSDU is defined as an elapsed time (unit: ms) from when “RLC SDU” isstored in Queue buffer provided with respect to each logical channel.Herein the timing of “when RLC SDU is stored in Queue buffer” is thesame between for the retransmission and for the initial transmission. Ifthere are RLC SDU having different Buffer residence time, the RLC SDUhaving the longest Buffer residence time is defined as flag_(DRX). Thisvalue is set based on the the buffer residence time “t_(RLC) _(—)_(buffered)” of RLC SDU as follows: F_(PC)(t_(RLC) _(—) _(buffered) <Th_(PC) ^((RLC) ^(—) ^(buffered))) = 0.0 F_(PC)(t_(RLC) _(—) _(buffered)≧ Th_(PC) ^((RLC) ^(—) ^(buffered))) = 1.0 As described above, byincreasing the value F_(PC)(t_(RLC) _(—) _(buffered)) when the bufferresidence time “t_(RLC) _(—) _(buffered)” of RLC SDU exceeds apredetermined value Th_(PC) ^((RLC) ^(—) ^(buffered)), it becomespossible to preferentially transfer data to UE having longer Bufferresidence time of RLC. 7 Th_(pc) ^((RLC) ^(—) ^(buffered)) Priority Thisis a threshold value related to the Buffer class residence time of theRLC SDU. 8 G(flag_(control)) UE This is a MAC control block prioritylevel coefficient used to preferentially transfer data to UE having MACcontrol block to be transmitted. In the sub-frame, this value is setbased on a value of flag_(control) of UE. When flag_(control) = 0, G(0)is set to a fixed value 1.0 (G(0) = 1.0), and only when flag_(control) =1, this value is set via external input interface (I/F). For example,when flag_(control) = 1, by setting G(flag_(control)) to 2.0(G(flag_(control)) = 2.0), it becomes possible to preferentiallytransmit remaining data of UE having the MAC control block to betransmitted. It is assumed that when there is MAC control block to betransmitted, flag_(control) is set to 1(flag_(oontrol) = 1), otherwise,flag_(oontrol) is set to 0 (flag_(control) = 0).. 9 R_(pc) ^((target))Priority This is a target data rate (bits/sub-frame) class 10 α^((CQI))UE This is a weighting coefficient with respect to priority level basedon CQI. By using this parameter, it becomes possible to put weighting onpriority levels based on CQI. 11 α_(pc) ^((retx)) Priority This is aweighting coefficient with respect to class priority level based on thenumber of HARQ retransmissions. By using this parameter, it becomespossible to put weighting on priority levels based on the number of HARQretransmissions. 12 α_(pc) ^((RLC) ^(—) ^(bufferred)) Priority This is aweighting coefficient with respect to class priority levels based onBuffer residence amount of RLC. By using this parameter, it becomespossible to put weighting on priority levels based on the Bufferresidence amount of RLC. 13 α_(pc) ^((freq)) Priority This is aweighting coefficient with respect to class priority levels based onfrequency of allocations.. By using this parameter, it becomes possibleto put weighting on priority levels based on the frequency ofallocations. 14 α_(pc) ^((rate)) Priority This is a weightingcoefficient with respect to class priority levels based on Average DataRate.. By using this parameter, it becomes possible to put weighting onpriority levels based on the Average Data Rate. 15 δ′_(pc) Priority Aconvergence value of user data speed class averaging forgettingcoefficient for R _(n, k) 16 τ′_(pc) Priority A convergence value ofallocation frequency class averaged forgetting coefficient used incalculating freq_(n, k). 17 Scheduling Priority An index of Schedulingpriority group set with priority group class respect to each Priorityclass. Prioritization index of each UE is performed in the order of“Scheduling priority group: High → Middle → Low”. Further, in each ofthe Scheduling priority groups, prioritization is performed based onscheduling coefficients. The priority order of the scheduling prioritygroup is defined as follows: High > Middle > Low.

Tables 3 and 4 show input parameters given to each logical channel ofeach user equipment (UE) with respect to each Sub-frame as a unit.

TABLE 3 No. Parameter name Remarks 1 PC_(n, k) This parameter indicatesPriority Class of the logical Channel #k of UE#n. Priority class refersto an index or class indicating a priority level of data defined withrespect to each logical channel. 2 R_(n) This parameter indicatesInstantaneous transmittable Data Rate (bits/sub-frame) of UE#ncalculated based on the following formula: Rn = DL_Table_TF_SIZE(RB_all,L CQIreceived ┘) Where RB_all: the number of RBs across the systembandwidth Further, “CQIreceived” is calculated as follows: (when DLtransmission type = Distributed) CQIreceived = CQI related to across thesystem bandwidth (when DL transmission type = Localized) CQIreceived =CQI of RBgroup having the highest quality The definition of the RBgroupcorresponds to the definition of the RB groups of CQI reported from UE.3 R _(n, k) This parameter indicates the Average Data Rate(bits/sub-frame) of logical channel #k of UE#n. R _(n, k)(TTI) =δ_(n, k) R _(n, k) (TTI − 1) + (1 − δ_(n, k))*r_(n, k) r_(n, k):instantaneous data rate As the initial value of R _(n, k), R_(n, k)calculated in the sub-frame is used. δ_(n, k): forgetting coefficientwhich is a variable changing with respect to each calculation period.Calculation of R _(n, k) is performed at every sub- frame based onupdate timing with respect to not only a logical channel having theHighest Priority but also any other logical channels.

TABLE 4 4 freq_(n,k) This parameter indicates a time-average value ofallocation frequency of logical channel #k of UE #n. An averagingsection (time) is designated by τ_(t). Namely Freq_(n,k)(TTI) =τ_(n,k)*freq_(n,k) (TTI − 1 ) + (1 − τ_(n,k))* Allocated_(n,k) Where,Allocated_(n,k) is set to 1 when DL-SCH is allocated to the data oflogical channel #k of UE #n in the sub-frame where there are data to betransmitted of logical channel #k of UE #n in data buffer; otherwise,Allocated_(n,k) is set to 0. Further, the update is to be performed withrespect to each sub-frame when there are data to be transmitted oflogical channel #k of UE #n in the data buffer. Calculation of“freq_(n,k)” is performed at every sub- frame based on update cycle withrespect to not only a logical channel having the Highest Priority butalso any other logical channels. 5 Freq_(PC) This parameter indicates avalue by averaging “freq_(n,k)” using UE# and logical channel # of thePriority class. Averaging is performed with respect to only UE# andlogical channel # having data to be transmitted in the data buffer atthe sub-frame. Namely calculated as follows:${Freq}_{PC} = \frac{\sum\limits_{\underset{Scheduling}{({n,{k\varepsilon PC}})}}\;{frrq}_{n,k}}{\sum\limits_{\underset{Scheduling}{({n,{k\varepsilon PC}})}}\; 1}$${Where}\mspace{14mu}{\sum\limits_{\underset{Scheduling}{({n,{k\varepsilon PC}})}}\mspace{14mu}{{denotes}\mspace{14mu}{the}\mspace{14mu}{sum}\mspace{14mu}(\Sigma)\mspace{14mu}{of}\mspace{14mu}{``{{UE}\# n\mspace{14mu}{and}}}}}$logical channels #k having Priority Class and there is data to betransmittd in the Buffer queue at the previous sub-frame”

Based on the input parameters in Tables 1 and 2, the Schedulingcoefficient C_(n) of the logical channel #h having the Highest priorityof the user equipment (UE) terminal #n is calculated based on formula(1) below.

$\begin{matrix}{C_{n} = {A_{{PC}_{h}} \times {B\left( {flag}_{HO} \right)} \times {D\left( {flag}_{DRX} \right)} \times {\alpha^{({CQI})} \cdot R_{n}} \times \left( {1 + {{\alpha_{{PC}_{h}}^{({retx})} \cdot E_{{PC}_{h}}}({retx})} + {\alpha_{{PC}_{h}}^{({RLC\_ buffered})} \cdot {F_{{PC}_{h}}\left( t_{RLC\_ buffered} \right)}}} \right) \times {G\left( {flag}_{control} \right)} \times {\exp\left( {{\alpha_{{PC}_{h}}^{({freq})} \cdot \left( {{Freq}_{PC} - {freq}_{n,h}} \right)} + {\alpha_{{PC}_{h}}^{({rate})} \cdot \left( {R_{n,h}^{({target})} - {\overset{\_}{R}}_{n,h}} \right)}} \right)}}} & (1)\end{matrix}$

Alternatively, the Scheduling coefficient C_(n) of the logical channel#h having the Highest priority of the user equipment (UE) terminal #nmay be calculated based on formula (1′) below.

$\begin{matrix}{C_{n} = {A_{{PC}_{h}} \times {B\left( {flag}_{HO} \right)} \times {D\left( {flag}_{DRX} \right)} \times {H\left( {flag}_{gap\_ control} \right)} \times {\alpha^{({CQI})} \cdot R_{n}} \times \left( {1 + {{\alpha_{{PC}_{h}}^{({retx})} \cdot E_{{PC}_{h}}}({retx})} + {\alpha_{{PC}_{h}}^{({RLC\_ buffered})} \cdot {F_{{PC}_{h}}\left( t_{RLC\_ buffered} \right)}}} \right) \times {G\left( {flag}_{control} \right)} \times {\exp\left( {{\alpha_{{PC}_{h}}^{({freq})} \cdot \left( {{Freq}_{PC} - {freq}_{n,h}} \right)} + {\alpha_{{PC}_{h}}^{({rate})} \cdot \left( {R_{n,h}^{({target})} - {\overset{\_}{R}}_{n,h}} \right)}} \right)}}} & \left( 1^{\prime} \right)\end{matrix}$

In formula (1′), a term of “H(flag_(gap) _(—) _(control))” is added tothe formula (1). The “flag_(gap) _(—) _(control)” is a flag indicatingwhether the user equipment (UE) is in a Measurement gap control mode.Herein, the Measurement gap control mode indicates whether a Measurementgap for measuring cells operating at a different frequency is beingapplied. When the Measurement gap control mode is ON, the Measurementgap is set at a predetermined timing. The Measurement gap is set fromthe base station apparatus.

Generally, in the sub-frame where the Measurement gap is applied, datacannot be transmitted and received. Therefore, it is necessary toallocate the radio resources to the user equipment #n to preferentiallytransmit and receive data in the sub-frame to which the Measurement gapis not applied. For example, by setting H(flag_(gap) _(—) _(control)) to10 (H(flag_(gap) _(—) _(control))=10) in a case of flag_(gap) _(—)_(control)=1 (i.e., Measurement gap control mode:ON) and H(flag_(gap)_(—) _(control)) is set to 1 (H(flag_(gap) _(—) _(control))=1) in a caseof flag_(gap) _(—) _(control)=0 (i.e., Measurement gap controlmode:OFF), it may become possible to perform the operation that“transmission and reception of data are preferentially performed withrespect to the sub-frames to which the Measurement gap is not applied”.

By the Measurement Gap Check in step S306, when the Measurement gapcontrol mode is ON and when the sub-frame is included in the Measurementgap or the sub-frame where the acknowledgement information (ACK/NACK) isto be received is included in the Measurement gap, this process in stepS320 is not performed. In other words, when the Measurement gap controlmode is ON and when this process in step S320 is to be performed, thesub-frame is at a timing when signals in the same (original) frequencyare transmitted and received in a mode when cells operating at adifferent frequency are being measured. Namely due to the term“H(flag_(gap) _(—) _(control))” it may become possible to preferentiallyallocate the shared channel to the mobile station (user equipment (UE)terminal) transmitting and receiving the same (original) frequency in amode when cells operating at a different frequency are being measured.

In a case of Intra-eNB Hand Over (Intra-eNB HO), it is assumed that themeasurement value and calculation value used for the scheduling are alsoused in a Target eNB (eNB of Handover destination).

In step S320, an Average Data Rate is measured.

The Average Data Rate is calculated using formula (2).R _(n,k) =R _(n,k)(N _(n,k)=1)R _(n,k)(TTI)=δ_(n,k) R _(n,k)(TTI−1)+(1−δ_(n,k))·r _(n,k)(N_(n,k)>1)  (2)

Where, N_(n,k)(1, 2, . . . ) denotes the number of updating the AverageData Rate. However, in the sub-frame where N_(n,k)=0, the followingformula (3) is applied.R _(n,k) =R _(n,k)  (3)

Further, a forgetting coefficient δ_(n,k) is calculated as follows.δ_(n,k)=min(1−1/N _(n,k),δ_(PCn,k))

An updating timing of the Average Data Rate is based on “every sub-framewhere there are data to be transmitted in the data buffer of the basestation apparatus 200”. Further, r_(n,k) is calculated as “a size oftransmitted MAC SDU”. Namely the calculation of the Average Data Rate isperformed based on any of the following operations in the sub-frame whenthe Average Data Rate is to be updated.

1. For a user equipment (UE) terminal that transmits data, the AverageData Rate is calculated assuming “r_(n,k)=size of transmitted MAC SDU”.

2. For a user equipment (UE) terminal that has not transmitted data, theAverage Data Rate is calculated assuming “r_(n,k)=0”.

In this case, the Average Data Rate is calculated when the result of theReceived CQI check is OK and conditions of updating the Average DataRate is matched. Namely the calculation is started after the CQI isreceived at least once.

Next, in step S322, N_(scheduling) indicating the number of userequipment (UE) terminals that calculate the Scheduling coefficient isincreased by 1 (one). In step S324, a value of “n” indicating the indexof the user equipment (UE) terminal is increased by 1 (one).

Next, in step S326, it is determined whether the value of “n” is equalto or less than N. When determining that the value of “n” is equal to orless than N (YES in step S326), the process goes back to step S304.

On the other hand, when determining that the value of “n” is greaterthan N (NO in step S326), the process goes to step S328 in which a UESelection process is performed. More specifically, in step S328, theuser equipment (UE) terminal is selected in which the allocation of theradio resources is performed based on the Dynamic scheduling withrespect to the sub-frame.

First, by the following formula, the number of user equipment (UE)terminals in which the radio resources are allocated based on theDynamic scheduling (i.e., the number of user equipment (UE) terminalsthat transmit the Downlink Shared Channel (DL-SCH)) N_(DL-SCH) iscalculated. Herein, a symbol N_(Scheduling) denotes the number of userequipment (UE) terminals in which the Scheduling Coefficient Calculationprocess has been performed (see FIG. 3).N _(DL-SCH)=min(N _(Scheduling) ,N _(DLMAX) −N _(PCH) −N_(RACHres))  (4)

Next, top N_(DL-SCH) user equipment (UE) terminals in which the resourceblocks are to be allocated based on the Dynamic scheduling are selectedin the descending order of the Scheduling coefficients calculated instep S320 with respect to each Scheduling priority group of the logicalchannel having the Highest priority. Namely user equipment (UE)terminals that become the transmission destinations of the downlinkShared Channel (DL-SCH) are selected. Herein, the Scheduling prioritygroup refers to a group prioritized in the Scheduling process and aScheduling priority group to which the logical channel is to belong isdefined with respect to each logical channel.

The above “user equipment (UE) terminals” are selected in accordancewith the order described below. When the user equipment (UE) terminalhas control information of the MAC layer to be transmitted in thesub-frame, the Scheduling priority group is set to “High” regardless ofthe Scheduling priority group of the logical channel having the Highestpriority.

High (1^(st))->High (2^(nd))-> . . . ->Middle (1^(st))->Middle(2^(nd))-> . . . ->Low (1^(St))->Low (2^(nd))-> . . .

As described above, it may become possible to calculate the Schedulingcoefficients with respect to each user equipment (UE) terminal that isdetermined to be able to transmit the downlink shared channel (DL-SCH)by performing a loop process with respect to “n” which is an index ofthe user equipment (UE index). Further, the radio resources areallocated to the user equipment (UE) terminals having a greatercalculated Scheduling coefficient value. Namely, by controlling thetransmission of the downlink shared channel (DL-SCH), in which DL-SCH istransmitted to the user equipment (UE) terminals having largerscheduling coefficients, it may become possible to determine the userequipment (UE) terminals to which the radio resources (downlink sharedchannel (DL-SCH)) are allocated and transmit the downlink shared channel(DL-SCH) to the user equipment (UE) terminals based on a priority levelof data, radio quality information reported from the user equipment (UE)terminals, the number of retransmission, whether there is controlinformation of the MAC layer, frequency of allocation, an average datarate, and a target data rate, whether the handover process is beingperformed, whether it is in a reception timing of an intermittentreception process, whether it is in a residence time of data in an RLC(Radio Link Control) layer, and whether it is in a reception timing in amode of measuring cells operated at a different frequency.

In the above example, the Scheduling priority group has three types,High, Middle, and Low. However, four or more types of the Schedulingpriority group may be provided, or two or less types of the Schedulingpriority group may be provided.

For example, five types, i.e., High_(MAC), High_(DRX), High, Middle, andLow, of the Scheduling priority group may be provided assuming that thepriority level decreases in the order of High_(MAC), High_(DRX), High,Middle, and Low. Further, in this case, with respect to the userequipment (UE) terminals having an MAC control block to be transmitted,the Scheduling priority may be set to “High_(MAC)” regardless of theScheduling priority group of the logical channel having the Highestpriority. Further, with respect to the user equipment (UE) terminal in aDRX reception timing in DRX mode, the Scheduling priority group may beset “High_(DRX)” regardless of the Scheduling priority group of thelogical channel having the Highest priority. By doing this, it maybecome possible to preferentially allocate the shared channel withrespect to the user equipment (UE) terminal having the MAC control blockto be transmitted and the user equipment (UE) terminal in the DRXreception timing in DRX mode. For example, when there are user equipment(UE) terminal(s) having the MAC control block and user equipment (UE)terminal(s) without the MAC control block, it may become possible topreferentially allocate the shared channel to the user equipment (UE)terminal(s) having the MAC control block regardless of the value ofC_(n) in formula (1).

In the above example, the priority level is set so that the prioritylevel decreases in the order of High_(MAC), High_(DRX), High, Middle,and Low. However, this is just an example only, and, for example, thepriority level may be set so that the priority level decreases in theorder of High, High_(MAC), High_(DRX), Middle, and Low.

Next, the downlink TFR Selection (DL TFR Selection) process performed instep S212 is described with reference to FIG. 4.

FIG. 4 shows a procedure of the DL TFR selection process. By performingthis procedure, it may become possible to determine the transmissionformats of and allocate the radio resources to common channels such asthe Synchronization Signal (also called a Synchronization channel(SCH)), the Broadcast Channel (BCH), the Paging Channel (PCH), and theRandom Access Channel (RACH) response (RACH response, or message2 inrandom access procedure), the Downlink Shared Channel (DL-SCH) to whichthe Persistent Scheduling is applied, and the Downlink Shared Channel(DL-SCH) to which the Dynamic Scheduling is applied.

First, in step S402, Resource blocks are allocated to the CommonChannels.

When the Synchronization signal is transmitted using the sub-frame, theresource blocks shown in Table 5 are allocated to the Synchronizationsignal. When the system bandwidth is 5 MHz, 10 MHz, and 20 MHz, 25, 50,and 100 resource blocks are provided in the system bandwidth,respectively. The resource blocks have the corresponding identificationnumbers starting from #0 for the resource block at one end. The RB groupincluding the RB allocated to the Synchronization signal is notallocated to the downlink shared channel (DL-SCH) to which the DynamicScheduling is applied. When the system bandwidth is 10 MHz or 20 MHz,six (6) resource blocks provided in the center portion of the systembandwidth are allocated to the Synchronization signal. Morespecifically, when the system bandwidth is 10 MHz, the resource blocks#22 through #27 are allocated to the Synchronization signal, and whensystem bandwidth is 20 MHz, the resource blocks #47 through #52 areallocated to the Synchronization signal. On the other hand, when thesystem bandwidth is 5 MHz, seven (7) resource blocks in the centerportion of the system bandwidth are allocated to the Synchronizationsignal. More specifically, when the system bandwidth is 5 MHz, theresource blocks #9 through #15 are allocated to the Synchronizationsignal.

The above-mentioned resource blocks allocated to the Synchronizationsignal are treated as the resource blocks reserved for theSynchronization signal to prevent the resource blocks from beingallocated to any other channel. However, not all the resource blockshaving been reserved for the Synchronization signal are practicallyallocated to the Synchronization signal. Namely the Synchronizationsignal is allocated to only predetermined sub-carriers among all theresource blocks having been allocated for the Synchronization signal.For example, the Synchronization signal is mapped to 72 sub-carriers inthe center portion of the system bandwidth and transmitted. In thiscase, when the number of the sub-carrier to which the Synchronizationsignal is mapped is defined as k, the “k” may be given as follows.

$\begin{matrix}{{k = {n - 36 + \left\lfloor \frac{N_{BW}^{DL}}{2} \right\rfloor}},{n = 0},\ldots\mspace{14mu},71} & (5)\end{matrix}$

Where, a symbol “N_(BW) ^(DL)” denotes the number of sub-carriers of theentire system bandwidth. In this case, when the system bandwidth is 5MHz, a group of sub-carriers to which the Synchronization signal ismapped does not correspond to the resource blocks to which the downlinkshared channel (DL-SCH) is mapped (see FIG. 5). Namely theSynchronization signal is transmitted as a group of sub-carriers whichis shifted with respect to the resource blocks to which the downlinkshared channel (DL-SCH) is mapped by 90 kHz (6 sub-carriers).

The transmission power of the Synchronization signal (total oftransmission power of all the resource elements (sub-carriers); absolutevalue; unit is W) is defined as P_(SCH).

TABLE A RB allocated to SCH RB Nos of RB to System bandwidth beallocated  5 MHz  #9~#15 10 MHz #22~#27 20 MHz #47~#52

When the Broadcast Channel (BCH) is transmitted via the sub-frame, theresource blocks shown in Table B are allocated to the Broadcast Channel(BCH). When the system bandwidth is 10 MHz or 20 MHz, six (6) resourceblocks in the center portion of the system bandwidth are allocated tothe Broadcast Channel (BCH). More specifically, when the systembandwidth is 10 MHz, the resource blocks #22 through #27 are allocatedto the Broadcast Channel (BCH), and when system bandwidth is 20 MHz, theresource blocks #47 through #52 are allocated to the Broadcast Channel(BCH). On the other hand, when the system bandwidth is 5 MHz, seven (7)resource blocks in the center portion of the system bandwidth areallocated to the Broadcast Channel (BCH). More specifically, when thesystem bandwidth is 5 MHz, the resource blocks #9 through #15 areallocated to the Broadcast Channel (BCH).

The above-mentioned resource blocks allocated to the Broadcast Channel(BCH) are treated as the resource blocks reserved for the BroadcastChannel (BCH) to prevent the resource blocks from being allocated to anyother channel. However, not all the resource blocks having been reservedfor the Broadcast Channel (BCH) are practically allocated to theBroadcast Channel (BCH). Namely, the Broadcast Channel (BCH) isallocated to only predetermined sub-carriers among all the resourceblocks having been allocated for the Broadcast Channel (BCH). Forexample, the Broadcast Channel (BCH) may be mapped to the sub-carriershaving the same sub-carrier numbers as the Synchronization signal ismapped. In this case, when the system bandwidth is 5 MHz, a group ofsub-carriers to which the Broadcast Channel (BCH) is mapped does notcorrespond to the resource blocks to which the downlink shared channel(DL-SCH) is mapped. Namely the Broadcast Channel (BCH) is transmitted asa group of sub-carriers which is shifted with respect to the resourceblocks to which the downlink shared channel (DL-SCH) is mapped by 90 kHz(6 sub-carriers).

Namely when the system bandwidth is 5 MHz, as shown in FIG. 5, the basestation apparatus 200 transmits the Broadcast Channel (BCH) via a groupof sub-carriers shifted with respect to the resource blocks to which thedownlink shared channel (DL-SCH) is mapped by 90 kHz (6 sub-carriers).

Further, when the system bandwidth is 5 MHz, the user equipment (UE)terminals 100 n receive the Broadcast Channel (BCH) via a group ofsub-carriers shifted with respect to the resource blocks to which thedownlink shared channel (DL-SCH) is mapped by 90 kHz (6 sub-carriers).

The transmission power of the Broadcast Channel (BCH) (total oftransmission power of all the resource elements (sub-carriers); absolutevalue; unit is W) is defined as P_(BCH).

The Broadcast Channel (BCH) is a name as the Transport Channel and iscalled a Common Control Physical Channel (CCPCH) as a physical channel.

TABLE B RB allocated to BCH RB Nos of RB to System bandwidth beallocated  5 MHz  #9~#15 10 MHz #22~#27 20 MHz #47~#52

When the Paging Channel (PCH) is to be transmitted via the sub-frame, anRB group set via the external input interface (I/F) is allocated to thePaging Channel (PCH). Further, a TRF selection process may be performedin accordance with the data size of the Paging Channel (PCH) or thenumber of the user equipment (UE) terminals to transmit the PagingChannel (PCH).

When a Random Access Channel response (RACH response) or Message2 inrandom access procedure is transmitted via the sub-frame, the number“Num_(RB,RACHres)” of resource blocks to be allocated to the RACHresponse is determined based on a CQI value “CQI_(RACHres)(i)” used forthe TRF selection process of the RACH response and the size“Size_(RACHres)” of the RACH response.

The size “Size_(RACHres)” of the RACH response is determined inaccordance with the number of user equipment (UE) terminals multiplexedon the RACH response and the transmission purpose of the RACH.

The CQI value “CQI_(RACHres)(i)” is set via the external input interface(I/F) with respect to each piece of quality information of the RACHpreamble. The symbol “i” is an index of the quality information and avalue indicating the lowest quality among the values of qualityinformation of the user equipment (UE) multiplexed in the RACH response(i.e., the smallest index value) is set.Num_(RB,RACHres) =DL_Table_(—) TF _(—) FRB(Size_(RACHres) ,CQI_(RACHres)(i)) (i=0, 1, 2, 3)

Further, until the number of the resource blocks allocated to the RACHresponse exceeds Num_(RB,RACHres), the RB groups are sequentiallyallocated to the RACH response in the ascending order of the RACH groupnumber.

Next, in step S404, RB allocation for Persistent Scheduling isperformed. Namely the Persistent Resource reserved in step S338 isallocated to the user equipment (UE) terminals having downlink sharedchannel (DL-SCH) to which the Persistent scheduling is applied in thesub-frame. In this case, the resource blocks to be allocated to thedownlink shared channel (DL-SCH) to which the Persistent scheduling isapplied are allocated by treating the RB group as a unit. Thetransmission power of the downlink shared channel (DL-SCH) to which thePersistent scheduling is applied (total of transmission power of all theresource elements (sub-carriers); absolute value; unit is W) is definedas P_(persist). Herein, when there are two or more user equipment (UE)terminals having the downlink shared channel (DL-SCH) to which thePersistent scheduling is applied, P_(persist) represents the totalamount of the transmission power of the downlink shared channel (DL-SCH)of all the user equipment (UE) terminals, the Persistent schedulingbeing applied to the downlink shared channel (DL-SCH).

Next, in step S406, a Calculation for Number of RBs for PDSCH (i.e., acalculation of the number of the resource blocks of the PhysicalDownlink Shared Channel (PDSCH)) is performed. More specifically, thenumber of the resource blocks “N_(dynamic) ^((RB))” that can beallocated to the Physical Downlink Shared Channel (PDSCH) using thefollowing formula (6) based on the maximum transmission power of thebase station apparatus 200 (hereinafter referred to as “P_(max)”:unit:W), transmission power of Synchronization signal “P_(SCH)”,transmission power of Broadcast Channel (BCH) “P_(BCH)”, transmissionpower of Paging Channel (PCH) “P_(PCH)”, transmission power of RandomAccess Channel (RACH) response “P_(RACHres)”, transmission power ofdownlink shared channel (DL-SCH) to which Persistent scheduling isapplied “P_(persist)” and transmission power per one resource block ofdownlink shared channel (DL-SCH) to which Dynamic scheduling is applied“P_(dynamic)”. Herein, a symbol “N_(dynamic) ^((RB))” denotes the numberof resource blocks of the entire system bandwidth, and symbols“N_(BCH)”, “N_(SCH)”, “N_(PCH)”, “N_(RACHres)”, and “N_(persist)” denotethe number of resource blocks allocated to the Broadcast Channel (BCH),Synchronization signal, Paging Channel (PCH), RACH response, and thedownlink shared channel (DL-SCH) to which the Persistent scheduling isapplied, respectively in the sub-frame.

$\begin{matrix}{{{N_{dynamic}^{({RB})} = {\min\left( {{N_{system}^{({RB})} - N_{common} - N_{persist}},\left\lfloor \frac{P_{\max} - {\max\left( {P_{SCH},P_{BCH}} \right)} - P_{persist} - P_{PCH} - P_{RACHres}}{P_{dynamic}^{({RB})}} \right\rfloor} \right)}}{N_{common} = {{\max\left( {N_{SCH},N_{BCH}} \right)} + N_{PCH} + N_{RACHres}}}}\mspace{70mu}} & (6)\end{matrix}$

When an inequality N_(dynamic) ^((RB))<N_(system)^((RB))−N_(common)−N_(persistent) is satisfied, the total transmissionpower value of the base station apparatus 200 is controlled so that thetotal transmission power value is equal to or less than the maximumtransmission power value of the base station apparatus 200 by preventingthe transmission using some RB group(s) among the RB groups other thanthe RB groups allocated to the BCH, PCH, RACH response, and downlinkshared channel (DL-SCH) to which Persistent scheduling is applied. Morespecifically, until the transmission of “N_(system)^((RB))−N_(common)−N_(persistent)−N_(dynamic) ^((RB))” or more resourceblocks is prohibited, the following process is performed to determinethe RB group that is prevented from being transmitted. In this process,first, a RB group having the smallest number of resource blocks isdetected and the transmission of the detected RB group is prohibited. Inthis case, if more than two RB groups having the smallest number ofresource blocks exists, the transmission of the RB groups issequentially prohibited in the ascending order of the RB group number.The above process is repeated to sequentially determine the RB groupsthat are prevented from being transmitted.

In step S408, a value of “k” is set to 1 (one) (k=1).

Next, in step S410, an RB Remaining Check process to determine whetherthere are any remaining resource blocks is performed.

More specifically, in step S410, it is determined whether there is anyremaining RB group that can be allocated to the downlink shared channel(DL-SCH) to which Dynamic scheduling is applied. When determining thatthere is an allocatable RB group, the OK is returned. On the other hand,when determining that there is no allocatable RB group, the NG isreturned. When a result of the RB Remaining Check is NG (NG in stepS410), the DL TFR Selection process is terminated.

The above-mentioned “RB group that can be allocated to the downlinkshared channel (DL-SCH) to which Dynamic scheduling is applied” refersto an RB group other than the RB groups having been allocated to any ofBCH, PCH, RACH response, DL-SCH to which Persistent scheduling isapplied, and DL-SCH to which Dynamic scheduling is applied and in whichthe TFR Selection process is already performed. Further, the number ofresource blocks included in the “RB groups that can be applied to thedownlink shared channel (DL-SCH) to which Dynamic scheduling is applied”is defined as N_(remain) ^((RB)).

In the above example, it is assumed that “RB group that can be allocatedto the downlink shared channel (DL-SCH) to which Dynamic scheduling isapplied” refers to an RB group other than the RB groups having beenallocated to any of BCH, PCH, RACH response, DL-SCH to which Persistentscheduling is applied, and DL-SCH to which Dynamic scheduling is appliedand in which the TFR Selection process is already performed. However,alternatively, the “RB group that can be allocated to the downlinkshared channel (DL-SCH) to which Dynamic scheduling is applied” may bean RB group other than the RB groups having been allocated to any ofSynchronization signal, BCH, PCH, RACH response, DL-SCH to whichPersistent scheduling is applied, and DL-SCH to which Dynamic schedulingis applied and in which the TFR Selection process is already performed.

On the other hand, when the result of the RB Remaining Check is OK (OKin step S410), the process goes to step S412.

Next, in step S412, the DL TFR Selection (Downlink TFR Selection)process is performed.

More specifically, the transport format of “the user equipment (UE)terminal in which radio resources are allocated based on Dynamicscheduling (excluding PCH and RACH response)” determined in step S212 isdetermined and the allocation of the RB groups is performed.

In the DL TFR selection process, a CQI adjustment process is performed.With respect to the CQI used in the TFR Selection process, the followingprocesses are applied; a frequency direction regarding process, anOuter-loop type offset adjustment process, and an offset process basedon the priority level of the logical channel having the Highestpriority.

Next, the frequency direction regarding process is described.

When the definition of the RB group of the CQI reported from the userequipment (UE) terminal is different from the definition of the RB groupin the DL TFR Selection process, the CQI values of the corresponding RBgroups reported from the user equipment (UE) (hereinafter referred to asCQI_(received)(j); j denotes RB group number) are regarded as the CQIvalues of the corresponding RB groups in the DL TFR Selection process(hereinafter referred to as CQI_(calibrated)(i); i denotes RB groupnumber). Further, when Best-M individual method is used as a method ofreporting the CQI value, it is assumed that the CQI value for the RBgroup having no CQI value is the same as the CQI value across the systembandwidth. When the Best-M individual method is applied, for example,the system bandwidth is divided into plural groups each having fourresource blocks, and CQI values with respect to each group of resourceblocks having four resource blocks are calculated, and top M CQI valuesof higher quality are reported from the user equipment to the basestation apparatus.

In the following, when the CQI related to the entire system bandwidth isexpressed, the argument is described as “all”.

For example, when N_(a) resource blocks of the RB group #a of the CQIreported from the user equipment (UE) and N_(b) resource blocks of theRB group #b of the CWI reported from the user equipment are included onRB group #i in the DL TFR Selection process, the CQI value of RB group#i in the DL TFR Selection process may be calculated based on thefollowing formula.

$\begin{matrix}{{{CQI}_{calibrated}(i)} = {10 \cdot {\log_{10}\left( \frac{{N_{a} \cdot 10^{\frac{{CQI}_{received}{(a)}}{10}}} + {N_{b} \cdot 10^{\frac{{CQI}_{received}{(b)}}{10}}}}{N_{a} + N_{b}} \right)}}} & (7)\end{matrix}$

Next, the Outer-loop type offset adjustment process (CQI_offsetadjustment) is described.

CQI_offset_(i) is adjusted like an Outer loop as shown in formula (8)based on the acknowledgement information (a result of CRC check) of thedownlink shared channel (DL-SCH) where the priority class of the logicalchannel having the Highest priority is X_(j,adjust). When the priorityclass of the logical channel having the Highest priority is other thanX_(j,adjust), the Outer-loop type offset adjustment process (in formula(8)) may not be performed.

The CQI_offset_(i) is adjusted with respect to each user equipment (UE)terminal. Further, Priority class X_(j,adjust) as the target of theCQI_offset adjustment process is set via the external input interface(I/F) with respect to each user equipment (UE) terminal.

Δ_(adj) ^((PC)) and BLER_(target) ^((PC)) may be configured to be setvia the external input interface (I/F). However, it is assumed that themaximum value of CQI_offset_(i) is defined as CQI_offset_(PC), and theminimum value of CQI_offset_(i) is defined as CQI_offset_(PC) ^((min)).The maximum value CQI_offset_(PC) ^((max)) and the minimum valueCQI_offset_(PC) ^((min)) of the CQI_offset_(i) are set via the externalinput interface (I/F). When the CQI_offset_(i) is fixed to the maximumvalue or the minimum value, the calculation of formula (8) is notperformed.

$\begin{matrix}{{CQI\_ offset}_{i} = \left\{ \begin{matrix}{{CQI\_ offset}_{i} + {\Delta_{adj}^{({PC}_{X})} \times {BLER}_{target}^{({PC}_{X})}}} & {{Input} = {``{Ack}"}} \\{{CQI\_ offset}_{i} - {\Delta_{adj}^{({PC}_{X})} \times \left( {1 - {BLER}_{target}^{({PC}_{X})}} \right)}} & {{Input} = {``{Nack}"}} \\{CQI\_ offset}_{i} & {{Input} = {``{DTX}"}}\end{matrix} \right.} & (8)\end{matrix}$

Then, the value of CQI_offset_(i) is added to the value of CQI of eachRB group and a value of CQI related to the entire system bandwidth as apower offset value. A process of the following formula is performed withrespect to each sub-frame in which the DL TFR Selection process isperformed regardless of “whether the priority class of the logicalchannel having the Highest priority is X_(j,adjust) in the sub-frame”.CQI _(adjusted)(i)=CQI _(adjusted)(i)+CQI_offset_(i)

Next, the offset process based on the priority level is described.

The CQI values of the corresponding RB groups and the CQI value relatedto the entire system bandwidth are adjusted using an offset value Δ_(PC)which is based on the priority level of the logical channel having theHighest priority. The Δ_(PC) may be set via the external input interface(I/F). The subscriber “pc” denotes Priority class.CQI _(adjust)(i)=CQI _(adjust)(i)−Δ_(PC)

Next, a resource block group allocation (RB group allocation) isdescribed. By performing the process below, the RB group is allocated tokth user equipment (UE) terminal in which radio resources are allocatedbased on the Dynamic Scheduling (excluding PCH and RACH response). FIG.6 schematically shows a DL_TF_Related_table and a case where CQI=1 as anexample.

Process

N_(remain) ^((RB)): the number of remaining resource blocks (Number ofRemaining RBs)

N_(capability): the maximum RB number determined based on UE category

N_(max,bit): the maximum data size (Payload size) determined based on UEcategoryN _(remain) ^((UE)) =N _(DL-SCH) −k+1

$\begin{matrix}{N_{allocated}^{({RB})} = {\min\left( {\left\lceil \frac{N_{remain}^{({RB})}}{N_{remain}^{({UE})}} \right\rceil,N_{capability}} \right)}} & (9)\end{matrix}$

When the downlink transmission type is Distributed, RB groups areselected so that the allocated frequency resources can be discretelydistributed within the system bandwidth until the number of the resourceblocks allocated to the user equipment (UE) terminal is equal to orgreater than N_(allocated) ^((UE)). For example, RB groups may bedefined in advance so that when the RB groups are sequentially allocatedin the ascending order of the RB group number, the allocated RB groupscan be discretely distributed; then the RB groups are sequentiallyallocated in the ascending order of the RB group number to the userequipment (UE) terminal.

When the downlink transmission type is not Distributed (i.e., when thedownlink transmission type is Localized), the RB groups are sequentiallyallocated to the user equipment (UE) terminal in the descending order ofthe value of CQI_(adjusted) of the RB groups until the number of theresource blocks allocated to the user equipment (UE) terminal is equalto or greater than N_(allocated) ^((UE)).

Hereinafter, the RB group determined “to be allocated to the userequipment (UE) terminal” in the process describe above may be referredto as a Temporary RB group.

In a case where the user equipment (UE) terminal has “the logicalchannel for which the Persistent Resource is reserved in step S338”, thePersistent Resource is added to the Temporary RB group.

When the logical channel having the Highest priority has retransmittabledata, data (MAC PDU) including RLC SDU having the maximum “bufferresidence time of the RLC SDU” of the logical channel having the Highestpriority are transmitted among the retransmittable data (MAC PDU).Herein, the definition of the buffer residence time of the RLC SDU isthe same as that of the RLC SDU buffer residence time described in No. 6of Table 1. It is assumed that the RB group used for the datatransmission is the same as the Temporary RB group; and the modulationscheme of the data transmission is the same as that in the initial datatransmission.

On the other hand, when the logical channel having the Highest prioritydoes not have retransmittable data, CQI_(TFR) is calculated as follows.

When the downlink transmission type is Distributed, it is given thatCQI_(TFR)=CQI_(adjusted) (all). On the other hand, when the downlinktransmission type is not Distributed (i.e. when the downlinktransmission type is Localized), CQI_(TFR)=CQI_(adjusted)(i) aretrue-value averaged across the bandwidth of the Temporary RB group (theaveraging is required to be performed by considering (the difference of)the number of resource blocks of each RB group).

The data size (DL-SCH) (hereinafter referred to as Size) and themodulation scheme (hereinafter referred to as Modulation) of thedownlink shared channel (DL-SCH) are determined by referring to aTF_related_table using the number of resource blocks in the Temporary RBgroup (RB_available) and CQI_(TFR) as arguments.Size=DL_Table_(—) TF_SIZE(RB_available,└CQI _(TFR)┘)Modulation=DL_Table_(—) TF_Mod(RB_available,└CQI_(TFR)┘)  (10)

In a case of Size>N_(max,bit), a value of CQI_(TFR) is repeatedlyreduced by 1 (one) until Size≦N_(max,bit) is satisfied (refer to a Tableof smaller CQI of a DL_TF_related_table, in this case, a value ofRB_available is not changed). Based on a confirmed value of Size, avalue of Modulation is changed to a value in accordance with theDL_TF_related_table.

Then, by the following procedure, the control information of the MAClayer and data of all logical channels in a data buffer are multiplexedwith the MAC PDU having the above Size. Herein, the data buffer may be,for example, an RLC buffer.

A case is described where there are plenty of data in the RLC buffer.

Step 1: First, when there is the control information of the MAC layer,the control information of the MAC layer is multiplexed with the highestpriority.

Step 2: Next, the data in the RLC buffer are sequentially extracted fromthe logical channels in the descending order of the priority level ofthe logical channel, and multiplexed. When there are two or more logicalchannels having the same priority level, if there are any DDCH, the DDCHis treated with the highest priority, and if there is no DDCH, the datain the RLC buffer may be sequentially extracted from the logicalchannels in any order. As a method of selecting the logical channel inany order, a Round-Robin method may be used.

Next, a case is described where there are no sufficient data in the RLCbuffer.

The number of resource blocks to be allocated NUM_(RB) is recalculatedby referring to the TF_related_table using the total size Size_(all) ofdata in the MAC control block and the RLC buffer of all logical channelsand CQI_(TFR) as argumentsNum_(RB) =DL_Table_(—) TF _(—) RB(Size_(all) ,└CQI _(TFR)┘)  (11)

When the downlink transmission type is Distributed, RB groups in theTemporary RB group are removed by repeating a process in which the RBgroup having the least number of resource blocks is removed, or whenthere are two or more RB groups having the same least number of resourceblocks, the RB groups are sequentially removed in the ascending order ofthe RB group number as long as the number of resource blocks to be usedfor transmission is equal to or greater than NUM_(RB) (removed RB groupsare used as (k+1)th radio resource or later of the user equipment (UE)).The number of resource blocks in the Temporary RB group after theprocess is performed is defined as NUM_(RB,F).

When the downlink transmission type is not Distributed, RB groups in theTemporary RB group are removed by repeating a process in which the RBgroup having the least value of CQI_(adjusted) is removed, or when thereare two or more RB groups having the same least value of CQI_(adjusted),the RB groups are sequentially removed in the ascending order of thenumber of resource blocks included in the RB groups, or when there aretwo or more RB groups having the same least value of CQI_(adjusted) andthe same least number of resource blocks, the RB groups are sequentiallyremoved in the descending order of the RB group number as long as thenumber of resource blocks to be used for transmission is equal to orgreater than NUM_(RB).

The RB groups removed in the above process are used as (k+1)th radioresource or later. The number of resource blocks in the Temporary RBgroup after the process is performed is defined as Num_(RB,F).Size=DL_Table_(—) TF_SIZE(Num_(RB,F) ,└CQI _(TFR)┘)Modulation=DL_Table_(—) TF_Mod(Num_(RB,F) ,└CQI _(TFR)┘)  (12)

Next, an RV Selection (Redundancy Version Selection) process in stepS414 is described.

The RV parameter in each retransmission time (a value which is zero (0)in the initial transmission) is set via the external input interface(I/F). The base station apparatus (eNB) 200 determines the value of theRV parameter based on the value of RSN. The RSN is set based on theestimated number of receiving the MAC PDU. Namely the RSN is set basedon the number of NACK of the HARQ-ACK for DL-SCH which is theacknowledgement information of the downlink shared channel (DL-SCH)received in Uplink (when a result of the ACK/NACK/DTX determinationresult of the HARQ-ACK for DL-SCH is DTX, a value of RSN is notincremented).

In step S416, the value of k is incremented. In step S418, it isdetermined whether the value of k is equal to or less than N_(DL-SCH).When determining that the value of k is equal to or less than N_(DL-SCH)(YES in step S418), the process goes back to step S410. On the otherhand, when determining that the value of k is not equal to or less thanN_(DL-SCH) (NO in step S418), the process is terminated.

Next, the base station apparatus 200 according to an embodiment of thepresent invention is described with reference to FIG. 7.

As shown in FIG. 7, the base station apparatus 200 according to anembodiment of the present invention includes a PCH RACH responsedetection section 204, a scheduling coefficient calculation section 206(as a selection unit), a transport format/resource block selectionsection 210 (as an allocation section), and a layer 1 processing section212.

The PCH RACH response detection section 204 performs the process of stepS206 described above. Specifically, the PCH RACH response detectionsection 204 counts the numbers of PCH and RACH response in the sub-frameand reports the results (counted numbers) to the scheduling coefficientcalculation section 206.

The scheduling coefficient calculation section 206 performs the processof step S208. Specifically, the scheduling coefficient calculationsection 206 selects user equipment (UE) terminals to which the radioresources are allocated based on the Dynamic scheduling in the sub-frameand reports the number “N_(DL-SCH)” of user equipment (UE) terminals towhich the radio resources are allocated based on the Dynamic schedulingto the transport format/resource block selection section 210.

The transport format/resource block selection section 210 performs theprocess of steps S212 and S214. Specifically, the transportformat/resource block selection section 210 performs downlink transportformat and resource selection. More specifically, the transportformat/resource block selection section 210 determines transmissionformats and allocates radio resources related to common channels such asthe Synchronization channel (SCH), the Broadcast Channel (BCH), thePaging Channel (PCH), and the Random Access Channel (RACH) response(RACH response), the Downlink Shared Channel (DL-SCH) to which thePersistent Scheduling is applied, and the Downlink Shared Channel(DL-SCH) to which the Dynamic Scheduling is applied.

The layer 1 processing section 212 performs a process related to thelayer 1.

Next, a user equipment (UE) terminal 100 _(n) is described withreference to FIG. 8.

As shown in FIG. 8, the user equipment (UE) terminal 100 _(n) includes atransmission/receiving antenna 102, an amplifier 104, atransmission/receiving section 106, a baseband signal processing section108, and an application section 110.

Regarding downlink data, a radio-frequency signal received by thetransmission/receiving antenna 102 is amplified in the amplifier 104 andfrequency-converted into a baseband signal in the transmission/receivingsection 106. This baseband signal is FFT processed and receptionprocessed such as error correction decoded and retransmission controlledin the baseband signal processing section 108. Downlink user data of thedownlink data are transmitted to the application section 110. Theapplication section 110 performs, for example, processes related to alayer higher than the physical layer or the MAC layer.

In this case, when the system bandwidth is 5 MHz, the baseband signalprocessing section 108 may have a capability of receiving BroadcastChannel (BCH) as shown in FIG. 5. Namely the baseband signal processingsection 108 may have a capability of receiving the Broadcast Channel(BCH) (CCPCH as a Physical Channel) mapped to sub-carriers shifted fromthe resource blocks to which downlink shared channel (DL-SCH) is mappedby 90 kHz (6 sub-carriers).

On the other hand, uplink data are transmitted from the applicationsection 110 to the baseband signal processing section 108. The basebandsignal processing section 108 performs a transmission process ofretransmission control (H-ARQ (Hybrid ARQ)), channel coding, an IFFTprocess and the like on the user data and outputs the user data to thetransmission/receiving section 106. The transmission/receiving section106 performs a frequency conversion to convert the baseband signaloutput from the baseband signal processing section 108 into a signal inradio frequency band. The signal is amplified in the amplifier 104 andtransmitted from the transmission/receiving antenna 102.

Second Embodiment

A radio communication system having a base station apparatus accordingto this embodiment of the present invention is applied is similar tothat described with reference to FIG. 1.

Similar to the first embodiment of the present invention describedabove, as shown in FIG. 1, the radio communication system 1000, whichmay be an Evolved UTRA (Universal Terrestrial Radio Access) and UTRAN(UTRA Network) system (a.k.a an LTE (Long Term Evolution) system or asuper 3G system), includes a base station apparatus (eNB: eNode B) 200and plural user equipment (UE) 100 _(n) (100 ₁, 100 ₂, 100 ₃, . . . 100_(n); n: an integer greater than zero (0)) (hereinafter, the userequipment (UE) may be referred to as a user equipment terminal(s)). Thebase station apparatus 200 is connected to an upper node station such asan access gateway apparatus 300. The access gateway apparatus 300 isconnected to a core network 400. In this case, the user equipment (UE)terminals 100 _(n) are in communication with the base station apparatus200 in a cell 50 based on the Evolved UTRA and UTRAN radio communicationscheme.

Each of the user equipment terminals (100 ₁, 100 ₂, 100 ₃, . . . 100_(n)) has the same configuration, functions, and status. Therefore,unless otherwise described, the term user equipment (UE) 100 _(n) may becollectively used in the following descriptions.

As the radio access scheme in the radio communication system 1000, theOFDM (Orthogonal Frequency Division Multiplexing) scheme and the SC-FDMA(Single-Carrier Frequency Division Multiplexing Access) scheme are usedin downlink and uplink communications, respectively. As described above,the OFDM scheme is a multi-carrier transmission scheme in which afrequency band is divided into plural sub-carriers having narrowfrequency bands and data are mapped on each sub-carrier to betransmitted. The SC-FDMA scheme is a single-carrier transmission schemein which a frequency band is divided so that different frequencies canbe used among plural terminals and as a result, interferences betweenterminals can be reduced.

Next, communication channels used in the Evolved UTRA and UTRAN radiocommunication scheme are described.

In downlink communications, a Physical Downlink Shared Channel (PDSCH)that is shared among the user equipment terminals 100 _(n) and aPhysical Downlink Control Channel (PDCCH) are used. In downlink, userinformation and transport format information of a Downlink SharedChannel, the user information and the transport information of an UplinkShared Channel, acknowledgement information of the Uplink Shared Channeland the like are reported via the Physical Downlink Control Channel(PDCCH). User data are transmitted via the Physical Downlink SharedChannel (PDSCH). The user data are transmitted via a Downlink SharedChannel (DL-SCH) as a transport channel.

In uplink communication, a Physical Uplink Shared Channel (PUSCH) thatis shared among user equipment terminals 100 _(n) and an LTE controlchannel are used. The LTE control channel has two types, one is to betime domain multiplexed with the Physical Uplink Shared Channel (PUSCH)and the other is to be frequency domain multiplexed with the PhysicalUplink Shared Channel (PUSCH). The control channel to be frequencydomain multiplexed with the Physical Uplink Shared Channel (PUSCH) iscalled a Physical Uplink Control Channel (PUCCH).

In uplink communication, a downlink Channel Quality Indicator (CQI) tobe used for scheduling in downlink and an Adaptive Modulation and Coding(AMC) and acknowledgement information of the Downlink Shared Channel(HARQ (Hybrid Automatic Repeat reQuest) ACK information) are transmittedvia the LTE control channel. Further, the user data are transmitted viathe Physical Uplink Shared Channel (PUSCH). The user data aretransmitted via an Uplink Shared Channel (UL-SCH) as a transportchannel.

Next, a Downlink MAC (DL MAC) data transmission procedure as acommunication control method performed in a base station apparatusaccording an embodiment of the present invention is described.

In this embodiment, a logical channel corresponds to, for example, aRadio bearer; and a Priority class corresponds to, for example, apriority level or Logical Channel Priority.

Next, an allocation unit of the transmission bandwidth of the PhysicalDownlink Shared Channel (PDSCH) is described. The allocation of thePhysical Downlink Shared Channel (PDSCH) is performed with respect toeach sub-frame by treating, for example, a Resource block group(hereinafter may be referred to as RB group) as a unit, the RB groupbeing defined as a system parameter. Each RB group includes pluralResource Blocks (RBs), and a corresponding relationship between the RBsand the RB group is set as a system parameter via an external inputinterface (I/F). The relationship between the resource blocks and the RBgroup is treated as a system parameter; however the relationship may bespecified using a fixed parameter in the apparatus. The allocation ofthe transmission bandwidth by treating the RB group as a unit may alsobe performed on the Physical Downlink Shared Channel (PDSCH) to whichPersistent scheduling is applied. In the following, a case is describedwhere the RB group is configured. However, without configuring the RBblock, the allocation of the Physical Downlink Shared Channel (PDSCH)may be performed by treating the resource block as a unit.

Further, in the descriptions below, a dynamic scheduling corresponds toa first resource allocation method of dynamically allocating radioresources. When the dynamic scheduling is applied to the Downlink SharedChannel (DL-SCH), radio resources are allocated to arbitrary sub-frameswith respect to the user equipment (UE). Further, in this case, variousvalues may be set as the values of the transmission format including theallocation information of the resource blocks as frequency resources,modulation scheme, payload size, HARQ information items, such as aRedundancy version parameter, a process number and the like, andinformation items of an MIMO and the like. The transmission format,i.e., allocation information of the resource blocks as frequencyresources, modulation scheme, payload size, HARQ information items, suchas a Redundancy version parameter, a process number and the like, andinformation items of an MIMO and the like, is reported to the userequipment (UE) terminal using DL scheduling information mapped to thephysical downlink control channel (PDCCH).

On the other hand, the Persistent scheduling is a scheduling method ofallocating transmission opportunities at a predetermined cycle inaccordance with a type of data or features of the application totransmit/receive data and corresponds to a second resource allocationmethod of allocating radio resources at the predetermined cycle. Namely,when the Persistent scheduling is applied to the Downlink Shared Channel(DL-SCH), the Downlink Shared Channel (DL-SCH) is transmitted usingpredetermined sub-frames with respect to the user equipment (UE).Further, in this case, predetermined values are set as the values of thetransmission format including the allocation information of the resourceblocks as frequency resources, modulation scheme, payload size, HARQinformation items, such as the Redundancy version parameter, the processnumber and the like, and the information items of the MIMO and the like.Namely, the shared channel (radio resource) is allocated to thepredetermined sub-frames, and the Downlink Shared Channel (DL-SCH) istransmitted using the predetermined transmission format. In this case,the predetermined sub-frames may be arranged, for example, at apredetermined cycle. Further, the predetermined transmission format isnot necessarily fixed to one type, and so, plural types of transmissionformats may be provided.

Next, a downlink MAC data transmission procedure is described withreference to FIG. 9. FIG. 9 shows a procedure from a scheduling processby calculating scheduling coefficients to a DL TFR selection process ofdetermining the transport format and the RB group to be allocated.

As shown in FIG. 9, in step S902, a DL MAC maximum multiplexing numberN_(DLMAX) is set in the base station apparatus 200. The DL MAC maximummultiplexing number N_(DLMAX) is the maximum multiplexing number in onesub-frame of the Downlink Shared Channel (DL-SCH) to which the DynamicScheduling is applied and is designated via the external input interface(I/F). Further, the DL MAC maximum multiplexing number N_(DLMAX) may bethe maximum number of the Downlink Scheduling Information transmitted inone sub-frame.

Next, in step S904, the base station apparatus 200 counts the number ofMCHs (MCH number) in the sub-frame and defines the numbers as N_(MCH).In this case, instead of using actual MCH number, the number of DownlinkScheduling Information for the MCH may be calculated as the MCH number.

Next, in step S906, the numbers of PCH, RACH response, D-BCH, and RACHmessage4 are counted, and the counted numbers are defined as N_(PCH),N_(RACHres), N_(D-BCH) and N_(RACHm4), respectively. In this case,however, as the numbers of the PCH, RACH response, D-BCH, and RACHmessage4, the number of Downlink Scheduling information for the PCH, thenumber of Downlink Scheduling information for the RACH response, thenumber of Downlink Scheduling information for the D-BCH, the number ofDownlink Scheduling information for the RACH message4, respectively maybe used. Further, in this process, with respect to the PCH, RACHresponse, D-BCH, and RACH message4, the numbers of the PCH, RACHresponse, D-BCH, and RACH message4 are counted. However, alternatively,only some of the PCH, RACH response, D-BCH, and RACH message4 may becounted, or a common channel other than the PCH, RACH response, D-BCH,and RACH message4 may similarly be counted, or a common channel otherthen any of the above channels may similarly be counted.

Next, in step S908, a calculation of scheduling coefficients isperformed in the base station apparatus 200. In this step, the userequipment (UE) terminals in which radio resources are allocated based onthe Dynamic scheduling in the sub-frame are selected. The number of userequipment (UE) terminals in which the radio resources are allocatedbased on the Dynamic scheduling in the sub-frame is defined asN_(DL-SCH).

Next, in step S912, a Downlink Transport format and Resource selection(DL TFR) is performed. Namely, transmission formats are determined andthe radio resources are allocated with respect to each of aSynchronization signal (also called a Synchronization Channel (SCH)), aPrimary Broadcast Channel (P-BCH), a Dynamic Broadcast Channel (D-BCH),a Paging Channel (PCH), a Random Access Channel (RACH) response (RACHresponse, or message2 in random access procedure), the Downlink SharedChannel (DL-SCH) to which MCH and the Persistent Scheduling is applied,and the Downlink Shared Channel (DL-SCH) to which the Dynamic Schedulingis applied.

Next, the Calculation for Scheduling coefficients performed in step S908is described with reference to FIG. 10.

FIG. 10 shows a process of selecting the user equipment (UE) terminal(s)in which radio resources are allocated based on the Dynamic schedulingby calculating the Scheduling coefficients. The base station apparatus200 performs the following processes with respect to all the userequipment (UE) terminals in the LTE active state including, for example,in the RRC (Radio Resource Control) connecting state.

As shown in FIG. 10, in step S1002, formulas of n=1 and N_(scheduling)=0are provided; where n denotes an index of the user equipment terminals100 _(n) and n=1, . . . , N (N is an integer greater than 0).

Next, in step S1004, Renewal of HARQ (Hybrid Automatic Repeat reQuest)Entity Status is performed. In this step, in the user equipment (UE), aprocess receiving ACK as the acknowledgement information with respect tothe Downlink Shared Channel (DL-SCH) is released. Further, a process inwhich the maximum number of retransmissions has been reached is alsoreleased and the user data in the process are discarded. The maximumnumber of retransmissions is set with respect to each Priority class viathe external input interface (I/F). Further, it is assumed that themaximum number of retransmissions of MAC PDU (Protocol Data Unit), inwhich plural logical channels are multiplexed, complies with the maximumnumber of retransmissions of a logical channel having the highestPriority Class.

Next, in step S1006, a Measurement Gap Check is performed. Morespecifically, it is determined whether the sub-frame (i.e., thesub-frame transmitting the Downlink Shared Channel (DL-SCH)) is includedin the Measurement Gap or whether the sub-frame receiving theacknowledgement information (ACK/NACK) with respect to the DownlinkShared Channel (DL-SCH) is included in the Measurement Gap. Whendetermining that the sub-frame is included in the Measurement Gap orthat the sub-frame receiving the acknowledgement information (ACK/NACK)is included in the Measurement Gap, an NG (signal) is returned,otherwise, an OK (signal) is returned. The Measurement Gap refers to atime interval when cells operating at a different frequency are measuredfor a different-frequency handover of the user equipment (UE), andduring the time interval, communications cannot be performed andtherefore, the user equipment (UE) cannot receive the Downlink SharedChannel (DL-SCH). Further, during the time period when measuring thecell operating at a different frequency, the user equipment (UE) cannottransmit the acknowledgement information (ACK/NACK). As a result, thebase station apparatus 200 cannot receive the acknowledgementinformation (ACK/NACK). Accordingly, when a result of the MeasurementGap Check is NG (NG in step S1006), the user equipment (UE) terminal isexcluded from a target of the scheduling process.

In this case, the cell operating at a different frequency may be a cellof the Evolved UTRA and UTRAN system or a cell of another system suchas, for example, GSM, WCDMA, TDD-CDMA, CDMA 2000, or WiMAX system.

When determining that a result of the Measurement Gap Check is OK (OK instep S1006), the process goes to step S1007 in which a Half Duplex Checkis performed. The Half Duplex refers to a communication method in whichuplink transmission and downlink transmission are not performedsimultaneously. In other words, in the Half Duplex, uplink transmissionand downlink transmission are performed at different timings.

In the Half Duplex Check process, when the user equipment (UE) terminalperforms the Half Duplex communication, the following six (6)determinations (D1 through D6 described below) may be made and if atleast one result is YES (correct) among the six determinations, the NGmay be returned, otherwise, the OK may be returned.

D1: whether the subframe, i.e., the sub-frame to transmit the downlinkshared channel (DL-SCH), overlaps the sub-frame to transmit uplinkshared channel (UL-SCH) in the user equipment (UE) terminal.

D2: whether the subframe, i.e., the sub-frame to transmit the downlinkshared channel (DL-SCH), overlaps the sub-frame to transmit at least oneof CQI (downlink radio quality information), a Sounding ReferenceSignal, a Scheduling Request (signal), and Random Access Channel (RACH)in the user equipment (UE) terminal.

D3: whether the subframe, i.e., the sub-frame to transmit the downlinkshared channel (DL-SCH), overlaps the sub-frame to transmit theacknowledgement information (ACK/NACK) with respect to the downlinkshared channel (DL-SCH) in the uplink of the user equipment (UE)terminal.

D4: when downlink shared channel (DL-SCH) is transmitted via thesub-frame, whether the sub-frame to transmit the acknowledgementinformation (ACK/NACK) with respect to the downlink shared channel(DL-SCH) in the uplink of the user equipment (UE) terminal overlaps thesub-frame to transmit the downlink shared channel (SynchronizationChannel (SCH))/Primary Broadcast Channel (P-BCH)/Dynamic BroadcastChannel (D-BCH)/MBMS channel.

D5: when downlink shared channel (DL-SCH) is transmitted via thesub-frame, whether the sub-frame to transmit the acknowledgementinformation (ACK/NACK) with respect to the downlink shared channel(DL-SCH) in the uplink of the user equipment (UE) terminal overlaps thesub-frame to transmit the acknowledgement information (ACK/NACK) withrespect to the uplink shared channel (DL-SCH) transmitted from the userequipment (UE) terminal before.

D6: when downlink shared channel (DL-SCH) is transmitted via thesub-frame, whether the sub-frame to transmit the acknowledgementinformation (ACK/NACK) with respect to the downlink shared channel(DL-SCH) in the uplink of the user equipment (UE) terminal overlaps thesub-frame to transmit the control information (Uplink Scheduling Grantand Downlink Scheduling Information) for uplink or downlink PersistentScheduling.

Further, regarding the uplink and downlink channels relevant to thedeterminations, all of the corresponding channels may be considered, oronly some of the corresponding channels may be considered. When a resultof the Half Duplex Check process is NG (NG in step S1007), the userequipment (UE) terminal is excluded from a target of the schedulingprocess.

As described above, upon performing uplink transmission, the userequipment (UE) terminal in Half Duplex cannot perform downlinktransmission. Therefore, by doing the process described above, namely bydetermining whether uplink transmission is to be performed in thesub-frame and performing a process not to transmit the downlinktransmission, it may become possible to avoid the problem that the userequipment (UE) terminal in Half Duplex cannot receive a downlinktransmission signal upon performing uplink transmission.

Further, in the six determinations described above, each determinationmay be made by considering a switching period required to switch betweendownlink reception and uplink transmission in the user equipment (UE)terminal. More specifically, for example, when the transmission timingof the acknowledgement information with respect to the downlink sharedchannel (DL-SCH) in the user equipment (UE) terminal or the transmissiontiming of the downlink shared channel (DL-SCH) in the base stationapparatus overlaps the switching timing, the result of the Half DuplexCheck process may be determined as “NG”.

In the above example, the Half Duplex Check process is performed withrespect to the user equipment (UE) terminal to communicate in HalfDuplex mode. However, the Half Duplex Check process may be performedwith respect to not only the user equipment (UE) terminal to communicatein Half Duplex mode but also the user equipment (UE) terminal tocommunicate in Full Duplex mode. Further, the Half Duplex Check processmay be performed with respect to all the user equipment (UE) terminalsto communicate in Full Duplex mode. Otherwise, the Half Duplex Checkprocess may be performed with respect to the user equipment (UE)terminal communicating in Full Duplex mode and having a value of pathloss between the user equipment (UE) terminal and the base stationapparatus 200 greater than a threshold value; and, on the other hand,the Half Duplex Check process may not be performed with respect to theuser equipment (UE) terminal communicating in Full Duplex mode andhaving a value of path loss between the user equipment (UE) terminal andthe base station apparatus 200 less than the threshold value. In thiscase, uplink transmission and downlink transmission are not performed atthe same time; therefore, it may become possible to avoid a problem that“uplink transmission signal in the user equipment (UE) terminal acts asan interference signal to a downlink receiving signal; and as a result,quality of downlink receiving signal is degraded” described below.Further, the Half Duplex Check process may be performed with respect toa user equipment (UE) terminal to communicate in Full Duplex mode in acell or a frequency band which may be heavily influenced by the problemthat “uplink transmission signal in the user equipment (UE) terminalacts as an interference signal to a downlink receiving signal; and as aresult, quality of downlink receiving signal is degraded”; and on theother hand, the Half Duplex Check process may not be performed withrespect to a user equipment (UE) terminal to communicate in Full Duplexmode in a cell or a frequency band which may not be heavily influencedby the problem that “uplink transmission signal in the user equipment(UE) terminal acts as an interference signal to a downlink receivingsignal; and as a result, quality of downlink receiving signal isdegraded”.

When a result of the Half Duplex Check process is OK (OK in step S1007),the process goes to step S1008 in which a Discontinuous Reception (DRX)Check process is performed. In step S1008, it is determined whether theuser equipment (UE) is in DRX (Discontinuous Reception) mode. Whendetermining that the user equipment (UE) is in DRX mode, it is furtherdetermined whether the sub-frame is included in a DRX reception timing.When determining that the user equipment (UE) is in DRX (DiscontinuousReception) mode and the sub-frame is not included in the DRX receptiontiming, the “NG” is returned, otherwise the “OK” is returned. Namelywhen determining that “the user equipment (UE) is not in DRX mode” orthat “the user equipment (UE) is in DRX mode and the sub-frame isincluded in the DRX reception timing”, the OK is returned. Further, “ina case of not being in DRX mode”, a value of flag_(DRX) described belowis set to 0 (zero); and “in a case of being in DRX mode and in DRXreception timing”, the value of flag_(DRX) is set to 1 (one). Herein,the DRX reception timing refers to a timing when data can be receivedduring DRX mode. The DRX reception timing may also be called“On-duration”. Further, when a state is in DRX mode and not in the DRXreception timing, the state corresponds to a sleep mode in which nodownlink signal is to be received.

Further, when a state is in DRX mode and in a retransmission timing ofthe data transmitted via the Persistent resource (i.e., “Sub-frame ofinitial transmission+HARQ RTT”˜“Sub-frame of initial transmission+HARQRTT+DRX Retransmission Timer”), the state may be regarded as the statein DRX mode and the DRX reception timing. Herein, the “DRXRetransmission Timer” refers to a parameter indicating a section whenretransmission with respect to the initial transmission may be performedand the parameter is set in advance between the base station apparatusand the user equipment (UE) terminal. Further, in the above example, theDRX Retransmission Timer is limited to the initial transmission.However, the DRX Retransmission Timer may be applied to a transmissionother than the initial transmission. Further, the value of the HARQ RTTmay be, for example, 8 sub-frames; otherwise, the value of the DRXRetransmission Timer may be, for example, 3 sub-frames. However, thevalues of 8 sub-frames and 3 sub-frames are examples only, and othervalues may also be applied.

When a result of the DRX Check process is NG (NG in step S1008), theuser equipment (UE) terminal is excluded from a target of the schedulingprocess.

On the other hand, when the result of the DRX Check process is OK (OK instep S1008), the process goes to step S1010 in which a Received CQI(Channel Quality Indicator) Check process is performed. Namely, a valueof CQI used in the sub-frame is obtained. For example, in a case wherethe base station apparatus 200 has ever received at least one CQI in thepast from the user equipment (UE) terminal, the latest CQI across thesystem bandwidth (Wideband CQI) and a UE Selected Sub-band CQI are usedin a process of step S1024 described below and the process in step S912.Further, for example, in a case where the base station apparatus 200 hasnever received—not even once—CQI from the user equipment (UE) terminalin the past, the CQI is set via the external input interface (I/F);namely a predetermined fixed CQI across the system bandwidth (WidebandCQI) is used in the process of step S1024 and the process of step S912.Further, the predetermined fixed CQI across the system bandwidth(Wideband CQI) may be, for example, stored as a parameter in theapparatus. Further, the predetermined fixed CQI across the systembandwidth (Wideband CQI) set via the external input interface (I/F) maybe calculated based on received SIR of the user equipment (UE) terminallocated at an edge portion of the cell.

Further, the base station apparatus 200 may determine the reliability ofreceived CQI; and when determining that the reliability is low, thereceived CQI may be regarded as not-received. Namely the phrase “hasever received at least one CQI in the past” may be regarded as “has everreceived at least one sufficiently reliable CQI in the past”. Otherwise,the phrase “latest CQI across the system bandwidth (Wideband CQI) and aUE Selected Sub-band CQI” may be regarded as “among sufficientlyreliable CQI, latest CQI across the system bandwidth (Wideband CQI) anda UE Selected Sub-band CQI”. Otherwise, the term “has never received—noteven once—CQI” may be regarded as “has never received—not even once—anysufficiently reliable CQI”. Further, the reliability of received CQI maybe determined based on, for example, the received quality of CQI such asthe SIR of CQI signal and more specifically based on the SIR of aDemodulation Reference Signal. Namely when the received quality value ofthe CQI is equal to or greater than a predetermined threshold value, itmay be determined that the reliability of the CQI is high; and when thereceived quality value of the CQI is less than the predeterminedthreshold value, it may be determined that the reliability of the CQI islow.

In step S1012, it is determined whether, in the sub-frame, thePersistent Resource is allocated to the user equipment terminal. Herein,the Persistent Resource refers to a Resource block reserved for thePersistent Scheduling. The Persistent scheduling is a scheduling methodof allocating transmission opportunities at a predetermined cycle inaccordance with a type of data or features of the application totransmit/receive data. Further, the type of data may include data ofVoice Over IP, Streaming data or the like. The Voice Over IP and theStreaming data correspond to the applications.

Herein, the Persistent Resource may be a resource allocated for theinitial transmission of the HARQ. In this case, when the data areretransmitted, the data are transmitted as the downlink shared channel(DL-SCH) to which the Dynamic Scheduling is applied. Namely regardingthe retransmission of the data, the transmission is performed byselecting the user equipment (UE) terminal to transmit the data based ona UE selection process of S1032 described below.

When determining that the Persistent resource is to be allocated (OK instep S1012), the process goes to step S1014 in which a Data Size Checkprocess is performed. When determining that the Persistent resource isnot to be allocated (NG in step S1012), the process goes to step S1020in which the Localized/Distributed Check process is performed. Inlocalized (transmission), it may be advantageous to allocate relativelyconsecutive frequency blocks (resource blocks) based on CQI because afading frequency in a propagation environment between the user equipment(UE) and the base station apparatus 200 is (relatively) small. On theother hand, in Distributed (transmission), it may be advantageous toallocate frequency blocks (resource blocks) which are relativelydiscretely distributed (separated) from each other regardless of the CQIvalues because the fading frequency in a propagation environment betweenthe user equipment (UE) and the base station apparatus 200 is(relatively) large. Further, the term “Localized” may also be called“Low Fd” (Fd: Fading frequency) and the term “Distributed” may also becalled “High Fd” (Fd: Fading frequency).

In step S1014, it is determined whether a size of the transmittable dataof the logical channel of the user equipment is equal to or greater thana threshold value Threshold_(data) _(—) _(size), the Persistentscheduling being applied to the logical channel. When determining thatthe size of the transmittable data is equal to or greater than thethreshold value Threshold_(data) _(—) _(size) (NG in step S1014), theprocess goes to step S1018 in which the Persistent Resource Releaseprocess is performed. On the other hand, when determining that the sizeof the transmittable data is less than the threshold valueThreshold_(data) _(—) _(size) (OK in step S1014), the process goes tostep S1016 in which a Persistent Resource Reservation process isperformed. In this case, it may be set in advance whether the PersistentScheduling is applied to each logical channel. For example, it may bedetermined that the Persistent Scheduling is applied to a logicalchannel transmitting VoIP data and the Dynamic Scheduling is applied tothe other logical channels.

Further, as the threshold value Threshold_(data) _(—) _(size), forexample, the maximum value that can be transmitted by the Persistentresource may be set.

In step S1016, the Persistent Resource to be allocated to the logicalchannel of the user equipment (UE) is reserved, the Persistentscheduling being applied to the logical channel. Further, thecalculation of the scheduling coefficients described below is alsoperformed with respect to the user equipment (UE) terminal to which thePersistent Resource is applied in the sub-frame. Further, when the radioresources are allocated to the logical channel to which the DynamicScheduling is applied in the sub-frame, the Persistent Resources arereleased, and the logical channel to which the Persistent scheduling isapplied and the logical channel to which the Dynamic scheduling isapplied are multiplexed with the Resource applied for the logicalchannel to which the Dynamic scheduling is applied, so that the MAC PDU(DL-SCH) is transmitted.

Further, the calculation of the scheduling coefficients in step S1024described below is also performed with respect to the user equipment(UE) terminal to which the Persistent Resource is applied in thesub-frame. Further, when transmission resources are allocated for thelogical channel to which the Dynamic Scheduling is applied in thesub-frame, the Persistent Resources are released, and the MAC PDU(DL-SCH) is transmitted to the user equipment (UE) terminal by using theResource allocated for the logical channel to which the Dynamicscheduling is applied. The method of multiplexing the data in the RLCbuffer of the MAC control block and each logical channel with the MACPDU is shown in step S912.

Herein, the MAC control block refers to control information of the MAClayer; otherwise, the MAC control block may be header information of theMAC layer.

In step S1018, the Persistent Resources to be allocated to the logicalchannel of the user equipment (UE) terminal are released, the Persistentscheduling being applied to the logical channel. In this case, withrespect to the Persistent Resources, it is assumed that only thesub-frame is released; and at the next timing when the next PersistentResource is allocated, the Data Size Check process (in step S1014) is tobe performed again.

In step S1020, the downlink transmission type (DL Transmission type) ofthe user equipment (UE) terminal is determined. Namely, it is determinedwhether the downlink transmission type is Localized (transmission) orDistributed (transmission). Further, the transmission type may becommonly managed with respect to both downlink transmission and uplinktransmission.

For example, when the Fd estimation value of the user equipment (UE)terminal is equal to or less than the threshold value Threshold_(Fd,DL),it is determined that the transmission type is Localized (transmission).Otherwise, it is determined that the transmission type is Distributed(transmission). As described above, the Localized transmission may alsobe called Low Fd, and the Distributed transmission may also be calledHigh Fd.

As the Fd estimation value, a value reported in the RRC message such asthe Measurement report from the user equipment (UE) terminal or a valuecalculated based on a time correlation value of the Sounding referencesignal transmitted from the user equipment (UE) terminal may also beused. Otherwise, the Fd estimation value may be calculated based on thetime correlation value of the Demodulation Reference Signal in thePhysical Uplink Shared Channel (PUSCH) transmitted from the userequipment (UE) terminal. Otherwise, the Fd estimation value may becalculated based on the time correlation value of the DemodulationReference Signal in the Physical Uplink Control Channel (PUCCH)transmitted from the user equipment (UE) terminal. Via the PhysicalUplink Control Channel (PUCCH), the acknowledgement information withrespect to the downlink shared channel (DL-SCH) and the downlink qualityinformation (CQI (Channel Quality Indicator)) are transmitted.

Next, in step S1022, a Buffer Status Check is performed. Morespecifically, with respect to the logical channel of the user equipment(UE), it is determined whether there are transmittable data in thesub-frame. Namely the base station apparatus 200 determines whetherthere are transmittable data in the data buffer with respect to eachlogical channel of the user equipment (UE). When determining that thereare no transmittable data in any of the logical channels, the NG isreturned. On the other hand, when determining that there aretransmittable data in at least one logical channel, the OK is returned.Herein, the transmittable data includes the data that can be newlytransmitted or the data that can be retransmitted.

However, in the following, exceptional processes in checking the bufferstatus are described.

With respect to the Logical channel when the transmission window of theRLC layer is Full and in stall mode, it is assumed that there are notransmittable data.

When it is decided that an instruction for the handover between the basestation apparatuses is to be sent to the user equipment (UE) terminal,with respect to a DTCH (Dedicated Traffic CHannel) in the logicalchannel of the user equipment (UE) terminal, it is assumed that thereare no transmittable data. Namely in this case, only the DownlinkControl Channel (DCCH) in the logical channel of the user equipment (UE)terminal is assumed to be transmittable data. Further, with respect toMAC control block, only when there is a MAC control block transmittableupon the transmission of the Downlink Control Channel (DCCH), thetransmission is performed. Further, with respect to the MAC controlblock, it may be assumed that there are transmittable data regardless ofthe existence of the Downlink Control Channel (DCCH). Otherwise, it maybe assumed that there are no transmittable data regardless of theexistence of the Downlink Control Channel (DCCH).

When the user equipment (UE) terminal hands over from another basestation (the source base station) apparatus to the base stationapparatus, it is assumed that there are no data transmittable to theuser equipment (UE) terminal until it is determined that data can betransmitted to the user equipment (UE) terminal. In this case, the basestation apparatus 200 may determine that data can be transmitted to theuser equipment (UE) terminal when, for example, the data transmissionfrom the other base station (the source base station) apparatus to thebase station apparatus is completed and a Status Report of the PDCPlayer is received. Further, the completion of the data transmission fromthe other base station (the source base station) apparatus to the basestation apparatus may be defined by when, for example, a timer is up bysetting the timer to count time required (estimated) to complete thedata transmission. Further, it is assumed that the determination ofwhether the Status Report of the PDCP layer is received is performedwith respect to only the logical channel designated for the transmissionof the Status Report of the PDCP layer.

When the uplink synchronization status of the user equipment (UE)terminal shows the synchronization loss, or when status of an uplinkdedicated resource is NG, it is assumed that there are no transmittabledata with respect to the DTCH of the user equipment (UE) terminal andthat only DCCH or MAC control block is regarded as the transmittabledata.

When the Persistent Resource is reserved in the sub-frame (i.e., theprocess of step S1016 is performed), it is assumed that there are notransmittable data with respect to the logical channel (the logicalchannel to which the Persistent Scheduling is applied). However, even inthis case, in the process of multiplexing the data in the RLC buffer ofthe MAC control block and each Logical Channel with the MAC PDU in stepS912, it is assumed that there are transmittable data.

When only there is a MAC control block as the transmittable data, thetransmittable data are treated as the logical channel belonging to thesame Priority class as the DCCH belongs. Namely, when only there is aMAC control block as the transmittable data, it is assumed that there isa signal corresponding to transmittable DCCH.

When the Persistent Resource is not reserved in the sub-frame (i.e., theprocess of step S1016 is not performed), the following process isperformed with respect to the Logical Channel to which the PersistentScheduling is applied.

When the Data size of the new transmittable data is equal to or greaterthan the threshold value Threshold_(data) _(—) _(size), or when thereare retransmittable data, it is assumed that there are transmittabledata.

On the other hand, when the Data size of the new transmittable data isless than the threshold value Threshold_(data) _(—) _(size), it isassumed that there are no transmittable data.

By performing this process, it may become possible to avoid that, in thesub-frame to which the Persistent Resource is not allocated, thetransmission resource is allocated to the data to which PersistentScheduling is to be applied. Further, unless otherwise described, aresult of the determination “whether there is transmittable data relatedto each logical channel” is also applied of the process of multiplexingthe data in the RLC buffer of the MAC control block and each LogicalChannel with the MAC PDU in step S912. Namely when determining that“there are no transmittable data”, it is assumed that there are notransmittable data as well in the process of multiplexing the data inthe RLC buffer of the MAC control block and each Logical Channel withthe MAC PDU in step S912.

When a result of the Buffer Status Check process is NG (NG in stepS1022), the user equipment (UE) terminal is excluded from a target ofthe scheduling process. On the other hand, when the result of the BufferStatus Check process is OK (OK in step S1022), the logical channelhaving the Highest priority is selected from among the logical channelhaving the transmittable data based on the following Selection logics,and the process goes to step S1024 in which the Scheduling CoefficientCalculation process is performed.

Selection logic 1: The logical channel having the highest priority isdefined as the logical channel having the Highest priority.

Selection logic 2: When there are plural logical channels satisfying theSelection logic 1, the logical channel(s) having the transmittable datais defined as the logical channel(s) having the Highest priority.

Selection logic 3: In a case where there are plural logical channelssatisfying the Selection logic 2, when there is a Dedicated ControlChannel (DCCH), the Dedicated Control Channel (DCCH) is defined as thelogical channel having the Highest priority; and when there is noDedicated Control Channel (DCCH), any of the logical channels from amongthe plural logical channel is determined as the logical channel havingthe Highest priority.

When those selection logics are applied, not the retransmission data ofthe logical channel having a lower priority but the new data of thelogical channel having a higher priority are more likely to bedetermined as the data of the logical channel having higher priority.

The above-described process that the user equipment is excluded from atarget of the scheduling process in steps S1006, S1008, and S1002 meansthat the Scheduling Coefficient Calculation process described below isnot to be performed. As a result, in the sub-frame, a Downlink SharedChannel (DSCH) is not transmitted to the user equipment (UE). In otherwords, the base station apparatus 200 performs the scheduling withrespect to the user equipment (UE) terminals other than the userequipment (UE) terminals determined to be excluded from the targets ofthe scheduling in the above steps S1006, S1008, or S1002; namely thebase station apparatus 200 selects user equipment (UE) terminals towhich the shared channel is to be transmitted and transmits downlinkshared channel (DL-SCH) to the selected user equipment (UE) terminals.

In step S1024, with respect to the logical channel determined as thelogical channel having the Highest priority in step S1022, theScheduling coefficients are calculated based on an evaluation formuladescribed below. Namely when there are plural logical channels withrespect to a certain user equipment (UE) terminal, the SchedulingCoefficient Calculation is not performed on all the logical channels butis performed only on the logical channel having the highest priority. Bydoing this, it may become possible to reduce the processing load of thebase station apparatus 200.

Tables 5 through 9 show parameters set via the external input interface(I/F).

TABLE 5 Set with respect No Parameter name to each Remarks 1 A_(pc)Priority This is a Priority Class Priority level class coefficient.Priority Class refers to an index or class indicating a priority levelof data defined with respect to each logical channel. 2 D(flag_(DRX)) UEA DRX priority level coefficient given to preferentially transmit dataof UE in DRX mode and DRX reception timing. In the sub-frame, this valueis set based on a value of flag “flag_(DRX)” related to the UE. Whenflag_(DRX) = 0, D(0) is set to a fixed value 1.0 (D(0) = 1.0), and onlywhen flag_(DRX) = 1, this value is set via external input interface(I/F). For example, when flag_(DRX) = 1 , by setting D(flag_(DRX)) to2.0 (D(flag_(DRX)) = 2.0), it becomes possible to preferentiallytransmit data of UE in DRX mode and DRX reception timing. It is assumedthat in DRX mode and DRX reception timing, flag_(DRX) is set to1(flag_(DRX) = 1), otherwise, flag_(DRX) is set to 0 (flag_(DRX) = 0). 3E_(PC)(Num_(retex)) Priority This is a retransmission prioritycoefficient class used to preferentially transmit data to UE having alarge number of retransmission of HARQ. When there are plurality ofProcesses having retransmission data, a value of the largest number ofthe retransmission is defined as Num_(retx). Depending on the value ofthe number of retransmission times, the setting value ofE_(PC)(Num_(retex)) is set as described above via the external inputinterface (I/F). For example, as shown in the table below By increasingthe value of E_(PC)(Num_(retex)) as the value of Num_(retx). increases,it becomes possible to preferentially transmit data to UE having a largenumber of retransmission of HARQ. Numretx setting value of EPC(Numretex)0 1.0 1 1.2 2, 3 1.8 4-16 2.5

TABLE 6 Set with respect No Parameter name to each Remarks 4F_(PC)(t_(RLC)_buffered) Priority This is a residence time prioritylevel coefficient used class to preferentially transmit data to UE inwhich buffer residence time of RLC is long. The buffer residence time ofRLC SDU related to a logical channel having the Highest priority is usedas an argument. The definition of buffer residence time of RLC SDU isdefined as an elapsed time (unit: ms) from when “RLC SDU” is stored inQueue buffer provided with respect to each logical channel. Herein thetiming of “when RLC SDU is stored in Queue buffer” is the same betweenfor the retransmission and for the initial transmission. If there areRLC SDU having different Buffer residence time, the RLC SDU having thelongest Buffer residence time is defined as flag_(DRX). This value isset based on the the buffer residence time “t_(RLC)_buffered” of RLC SDUas follows: [t_(RLC)_buffered< Th_(PC) ^((RLC)_buffered,1)]F_(PC)(t_(RLC)_buffered) = 0.0 [Th_(PC) ^((RLC)_buffered,1) ≦t_(RLC)_buffered < Th_(PC) ^((RLC)_buffered,2)]${F_{PC}\left( t_{{RLC}\_{buffered}} \right)} = \frac{t_{{RLC} - {buffered}} - {Th}_{LCP}^{({{{RLC}\_{buffered}},1})}}{{Th}_{LCP}^{({{{RLC} - {buffered}},2})} - {Th}_{LCP}^{({{{RLC} - {buffered}},1})}}$However when Th_(LCP) ^((RLC−buffered,1)) = Th_(LCP) ^((RLC−buffered,2))is satisfied, this process is ineffective. [Th_(PC) ^((RLC)_buffered,2)≦ t_(RLC)_buffered] F_(PC)(t_(RLC)_buffered ≧ Th_(PC) ^(RLC)_buffered))= 1.0

As described above, by increasing the value F_(PC)(t_(RLC)_buffered)when the buffer residence time “t_(RLC)_buffered” of RLC SDU exceeds apredetermined value Th_(PC) ^((RLC)_buffered), it becomes possible topreferentially transfer data to UE having longer Buffer residence timeof RLC.

TABLE 7 Set with respect No Parameter name to each Remarks 5 Th_(pc)^((RLC) ^(—) ^(buffered, 1)) Priority This is a threshold value relatedto the Buffer class residence time of the RLC SDU. 6 Th_(pc) ^((RLC)^(—) ^(buffered, 2)) Priority This is a threshold value related to theBuffer class residence time of the RLC SDU. 7 G(flag_(control)) UE Thisis a MAC control block priority level coefficient used to preferentiallytransfer data to UE having MAC control block to be transmitted. In thesub-frame, this value is set based on a value of flag_(control) of UE.When flag_(control) = 0, G(0) is set to a fixed value 1.0 (G(0) = 1.0),and only when flag_(control) = 1, this value is set via external inputinterface (I/F). For example, when flag_(control) = 1, by settingG(flag_(control)) to 2.0 (G(flag_(control)) = 2.0), it becomes possibleto preferentially transmit remaining data of UE having the MAC controlblock to be transmitted. It is assumed that when there is MAC controlblock to be transmitted, flag_(control) is set to 1(flag_(control) = 1),otherwise, flag_(control) is set to 0 flag_(control) = 0).. 8 R_(pc)^((target)) Priority This is a target data rate (bits/sub-frame) class 9α^((CQI)) UE This is a weighting coefficient with respect to prioritylevel based on CQI. By using this parameter, it becomes possible to putweighting on priority levels based on CQI.

TABLE 8 Set with respect No Parameter name to each Remarks 10 α_(pc)^((retx)) Priority This is a weighting coefficient with respect to classpriority level based on the number of HARQ retransmissions. By usingthis parameter, it becomes possible to put weighting on priority levelsbased on the number of HARQ retransmissions. 11 α_(pc) ^((RLC) ^(—)^(bufferred)) Priority This is a weighting coefficient with respect toclass priority levels based on Buffer residence amount of RLC. By usingthis parameter, it becomes possible to put weighting on priority levelsbased on the Buffer residence amount of RLC. 12 α_(pc) ^((rate))Priority This is a weighting coefficient with respect to class prioritylevels based on Average Data Rate. By using this parameter, it becomespossible to put weighting on priority levels based on the Average DataRate. 13 δ′_(pc) Priority A convergence value of user data speedaveraging class forgetting coefficient for R _(n, k) 14 SchedulingPriority An index of Scheduling priority group set with priority groupclass respect to each Priority class. Prioritization of index each UE isperformed in the order of “Scheduling priority group: High → Middle →Low”. Further, in each of the Scheduling priority groups, prioritizationis performed based on scheduling coefficients. The priority order of thescheduling priority group is defined as follows: High > Middle > Low.

Table 9 shows input parameters given to each logical channel of eachuser equipment (UE) terminal by treating the sub-frame as a unit.

TABLE 9 No. Parameter name Remarks 1 PC_(n, k) This parameter indicatesPriority Class of the logical Channel #k of UE#n. Priority class refersto an index or class indicating a priority level of data defined withrespect to each logical channel. 2 R_(n) This parameter indicatesInstantaneous transmittable Data Rate (bits/sub-frame) of UE#ncalculated based on the following formula: Rn = DL_Table_TF_SIZE(RB_all,L CQIreceived ┘) Where RB_all: the number of RBs across the systembandwidth Further, “CQIreceived” is calculated as follows: (when DLtransmission type = Distributed) CQIreceived = CQI related to across thesystem bandwidth (when DL transmission type = Localized) CQIreceived =CQI of RBgroup having the highest quality The definition of the RBgroupcorresponds to the definition of the RB groups of CQI reported from UE.3 R _(n, k) This parameter indicates the Average Data Rate(bits/sub-frame) of logical channel #k of UE#n. R _(n, k)(TTI) =δ_(n, k) R _(n, k) (TTI − 1) + (1 − δ_(n, k))*r_(n, k) r_(n, k):instantaneous data rate As the initial value of R _(n, k), R_(n, k)calculated in the sub-frame is used δ_(n, k): forgetting coefficientwhich is a variable changing with respect to each claculation periodCalculation of R _(n, k) is performed at every sub- frame based onupdate timing with respect to not only a logical channel having theHighest Priority but also any other logical channels.

Based on the input parameters in Tables 5-8, the Scheduling coefficientC_(n) of the logical channel #h having the Highest priority of the userequipment (UE) terminal #n is calculated based on formula (1) below.

$\begin{matrix}{C_{n} = {A_{{LCP}_{h}} \times {D\left( {flag}_{DRX} \right)} \times {\alpha^{({CQI})} \cdot R_{n}} \times \left( {1 + {{\alpha_{{LCP}_{h}}^{({retx})} \cdot E_{{LCP}_{h}}}({retx})} + {\alpha_{{LCP}_{h}}^{({RLC\_ buffered})} \cdot {F_{{LCP}_{h}}\left( t_{RLC\_ buffered} \right)}}} \right) \times G\left( {flag}_{control} \right) \times {\exp\left( {\alpha_{{LCP}_{h}}^{({rate})} \cdot \left( {R_{n,h}^{({target})} - {\overset{\_}{R}}_{n,h}} \right)} \right)}}} & (13)\end{matrix}$

Further, in a case of Intra-eNB Hand Over (Intra-eNB HO), it is assumedthat the measured value and calculated value used for the Scheduling arenot taken over into the Target eNB (eNB of handover destination).

In step S1024, the Average Data Rate is measured.

The Average Data Rate is obtained by using the formula (2) describedabove.

Where, N_(n,k)(1, 2, . . . ) denotes the number of updating the AverageData Rate. However, in the sub-frame where N_(n,k)=0, the formula (3)described above is applied.

Further, a forgetting coefficient δ_(n,k) is calculated as follows.δ_(n,k)=min(1−1/N _(n,kr),δ′_(PCn,k))

An updating timing of the Average Data Rate is based on “every sub-framewhere there are data to be transmitted to the data buffer of the logicalchannel #k of the base station apparatus 200”. Further, r_(n,k) iscalculated as a transmitted “size of transmitted MAC SDU”. Namely thecalculation of the Average Data Rate is performed based on any of thefollowing operations in the sub-frame when the Average Data Rate is tobe updated.

1. For a user equipment (UE) terminal that transmits data, the AverageData Rate is calculated assuming “r_(n,k)=size of transmitted MAC SDU”.

2. For a user equipment (UE) terminal that has not transmitted data, theAverage Data Rate is calculated assuming “r_(n,k)=0”.

In this case, the Average Data Rate is calculated when determining thatat least one CQI is received in the past in the Received CQI Checkprocess and conditions of updating the Average Data Rate are matched.Namely the calculation is started after the CQI is received at leastonce.

Next, in step S1026, N_(scheduling) indicating the number of userequipment (UE) terminals that calculate the Scheduling coefficient isincreased by 1 (one). In step S1028, a value of “n” indicating the indexof the user equipment (UE) terminal is increased by 1 (one).

Next, in step S1030, it is determined whether n is equal to or less thanN. When determining that n is equal to or less than N (YES in stepS1030), the process goes back to step S1004.

On the other hand, when determining that n is greater than N (NO in stepS1030), the process goes to step S1032 in which a UE Selection processis performed. More specifically, in step S1032, the user equipment (UE)terminal is selected in which the allocation of the radio resources isperformed based on the Dynamic scheduling with respect to the sub-frame.

First, by the following formula, the number “N_(DL-SCH)” of userequipment (UE) terminals in which the radio resources are allocatedbased on the Dynamic scheduling (i.e., the number of user equipment (UE)terminals transmitting the Downlink Shared Channel (DL-SCH)) iscalculated. Herein, a symbol N_(Scheduling) denotes the number of userequipment (UE) terminals in which the Scheduling Coefficient Calculationprocess has been performed (see FIG. 10).N _(DL-SCH)=min(N _(scheduling) ,N _(DLMAX) −N _(PCH) −N _(RACHres) −N_(D-BCH) −N _(RACHm4) −N _(MCH))

When the number “N_(DL-SCH)” of user equipment (UE) terminalstransmitting the Downlink Shared Channel (DL-SCH)) is calculated, ifinequality N_(DL-SCH)<0 is satisfied, the transmission process of thesub-frame is sequentially prohibited in the order of RACH message4, RACHresponse, MCH, PCH, and D-BCH. When determined that the transmission ofthe sub-frame is prohibited in a channel, the channel is not transmittedusing the sub-frame.

Next, top N_(DL-SCH) user equipment (UE) terminals in which the resourceblocks are allocated based on the Dynamic scheduling are selected, thetop N_(DL-SCH) user equipment (UE) terminals having larger Schedulingcoefficients calculated in step S1024 with respect to each Schedulingpriority group of the logical channel having the Highest priority.Namely user equipment (UE) terminals that become the transmissiondestinations of the downlink Shared Channel (DL-SCH) are selected.Herein, the Scheduling priority group refers to a group prioritized inthe Scheduling process and a Scheduling priority group to which thelogical channel is to belong is defined with respect to each logicalchannel. Namely each user equipment (UE) terminal is classified(hierarchized) into the Scheduling priority groups based on the logicalchannel having the Highest priority; and in each of the Schedulingpriority groups, user equipment (UE) terminals to become thedestinations of the downlink shared channel (DL-SCH) to which theDynamic scheduling is applied are sequentially selected in thedescending order of the Scheduling Coefficients calculated in step S1024(i.e., the scheduling (process) is performed).

The above “user equipment (UE) terminals” are selected in accordancewith the following order.

High(1^(st))->High(2^(nd))-> . . . ->Middle(1^(st))->Middle(2^(nd))-> .. . ->Low(1^(st))->Low(2^(nd))-> . . .

When the user equipment (UE) terminal has control information of the MAClayer to be transmitted in the sub-frame, the Scheduling priority groupis set to “High” regardless of the Scheduling priority group of thelogical channel having the Highest priority. Namely, the base stationapparatus 200 performs the Scheduling assuming that, in the sub-frame,the user equipment (UE) terminal having the control information of theMAC layer to be transmitted belongs to the Scheduling priority grouphaving higher priority level.

Further, in the above example, the Scheduling priority group has threetypes, High, Middle, and Low. However, for example, Super High may beadded and defined. In this case, for example, a priority level flagwhich is set only when a congestion degree of the cell is high isdefined, and the user equipment (UE) terminal or the logical channel inwhich the priority level flag is ON may be assumed to belong to theSuper High Scheduling priority group. The user equipment (UE) terminalor the logical channel in which the priority level flag is set maytransmit/receive an emergency call or a priority call. Further, when thecongestion degree of the cell is high, the base station apparatus 200may reserve resources in the base station apparatus 200 for the userequipment (UE) terminal or the logical channel in which the prioritylevel flag is set. Further, the resources may include CPU capacity,memory capacity, baseband resource, transmission power resource,frequency resource, resource in time direction and the like. Further, toreserve the resources, the number of the user equipment (UE) terminalsmay be limited; namely the maximum number of user equipment (UE)terminals to be connected in the cell may be reduced.

Further, with respect to the user equipment (UE) terminal in which thepriority level flag is set or the user equipment (UE) terminal having alogical channel in which the priority level flag is set, all the logicalchannel provided in the user equipment (UE) terminal may belong to theSuper High Scheduling priority group. In this case, to any of thelogical channels provided in the user equipment (UE) terminal, resourcesare preferentially allocated, i.e., shared channels are allocated.

The priority level flag may be reported from the core network.

As described above, it may become possible to calculate the Schedulingcoefficients with respect to each user equipment (UE) terminal that isdetermined to be able to transmit the downlink shared channel (DL-SCH)by performing the loop process with respect to “n” which is the index ofthe user equipment (UE index). Further, the radio resources areallocated to the user equipment (UE) terminals having a greatercalculated Scheduling coefficient value. Namely it may become possibleto determine the user equipment (UE) terminals to which the radioresources (downlink shared channel (DL-SCH)) are allocated and transmitthe downlink shared channel (DL-SCH) to the user equipment (UE)terminals based on the priority level of data, radio quality informationreported from the user equipment (UE) terminal, the number ofretransmission, whether there is control information of the MAC layer,frequency of allocation, the average data rate, and the target datarate, whether the handover process is being performed, whether it is inthe reception timing of the intermittent reception process, whether itis in a residence time of data in the RLC (Radio Link Control) layer,and whether it is in the reception timing in the mode of measuring acell operated at a different frequency by performing control oftransmitting the downlink shared channel (DL-SCH), in which DL-SCH istransmitted to the user equipment (UE) terminals having largerscheduling coefficients.

In the above example, the Scheduling priority group has three types,High, Middle, and Low. However, four or more types of the Schedulingpriority group may be provided, or two or less types of the Schedulingpriority group may be provided.

For example, five types, i.e., High_(MAC), High_(DRX), High, Middle, andLow, of the Scheduling priority groups may be provided assuming that thepriority level decreases in the order of High_(MAC), High_(DRX), High,Middle, and Low. Further, in this case, with respect to the userequipment (UE) terminals having an MAC control block to be transmitted,the Scheduling priority may be set to “High_(MAC)” regardless of theScheduling priority group of the logical channel having the Highestpriority. Further, with respect to the user equipment (UE) terminal in aDRX reception timing in DRX mode, the Scheduling priority group may beset “High_(DRX)” regardless of the Scheduling priority group of thelogical channel having the Highest priority. By doing this, it maybecome possible to preferentially allocate the shared channel withrespect to the user equipment (UE) terminal having the MAC control blockto be transmitted and the user equipment (UE) terminal in the DRXreception timing in DRX mode. For example, when there are user equipment(UE) terminal(s) having the MAC control block and user equipment (UE)terminal(s) without the MAC control block, it may become possible topreferentially allocate the shared channel to the user equipment (UE)terminal(s) having the MAC control block regardless of the value ofC_(n) in formula (1).

In the above example, the priority level is set so that the prioritylevel decreases in the order of High_(MAC), High_(DRX), High, Middle,and Low. However, this is just an example only, and, for example, thepriority level may be set so that the priority level decreases in theorder of High, High_(MAC), High_(DRX), Middle, and Low.

Next, the downlink TFR Selection (DL TFR Selection) process performed instep S912 is described with reference to FIG. 11.

FIG. 11 shows a procedure of the DL TFR selection process. By performingthis procedure, it may become possible to determine the transmissionformats of and allocate the radio resources to the SynchronizationSignal (also called a Synchronization channel (SCH)), the PrimaryBroadcast Channel (P-BCH), the Paging Channel (PCH), the DynamicBroadcast Channel (D-BCH), the Random Access Channel (RACH) response(RACH response, or message2 in random access procedure), the Message4 inrandom access procedure, the MBMS channel (MCH), the Downlink SharedChannel (DL-SCH) to which the Persistent Scheduling is applied, and theDownlink Shared Channel (DL-SCH) to which the Dynamic Scheduling isapplied. The above SCH, P-BCH, PCH, D-BCH, RACH response, RACH Message4are called common channels.

First, in step S1102, Resource Blocks are allocated to the CommonChannels (RB allocation for Common channel is performed).

When the Synchronization signal is transmitted using the sub-frame, sixor seven resource blocks in the substantially center portion of thesystem bandwidth are allocated to the Synchronization signal. The RBgroup including the RB allocated to the Synchronization signal is notallocated to the downlink shared channel (DL-SCH) to which the DynamicScheduling is applied.

The above-mentioned resource blocks allocated to the Synchronizationsignal are treated as the resource blocks reserved for theSynchronization signal to prevent the resource blocks from beingallocated to any other channel. However, not all the resource blockshaving been reserved for the Synchronization signal are practicallyallocated to the Synchronization signal. Namely the Synchronizationsignal is allocated to only predetermined sub-carriers among all theresource blocks having been allocated for the Synchronization signal.

The transmission power of the Synchronization signal (total oftransmission power of all the resource elements (sub-carriers); absolutevalue; unit is W) is defined as P_(SCH).

When the Primary Broadcast Channel (P-BCH) is transmitted via thesub-frame, six or seven resource blocks in the substantially centerportion of the system bandwidth are allocated to the Primary BroadcastChannel (P-BCH). The above-mentioned resource blocks allocated to thePrimary Broadcast Channel (P-BCH) are treated as the resource blocksreserved for the Primary Broadcast Channel (P-BCH) to prevent theresource blocks from being allocated to any other channel. However, notall the resource blocks having been reserved for Primary BroadcastChannel (P-BCH) are practically allocated to the Primary BroadcastChannel (P-BCH). Namely the Primary Broadcast Channel (P-BCH) isallocated to only predetermined sub-carriers among all the resourceblocks having been allocated for the Primary Broadcast Channel (P-BCH).For example, the Primary Broadcast Channel (P-BCH) may be mapped to thesub-carriers having the same sub-carrier numbers as the Synchronizationsignal is mapped.

The transmission power of the Primary Broadcast Channel (P-BCH) (totalof transmission power of all the resource elements (sub-carriers);absolute value; unit is W) is defined as P_(P-BCH).

When the Paging Channel (PCH) is transmitted via the sub-frame, the RBgroup determined in advance is allocated to the Paging Channel (PCH).Otherwise, in accordance with the data size of the Paging Channel (PCH)or the number of user equipment (UE) terminals transmitting the PagingChannel (PCH), or in accordance with available RB group, the RB groupmay be allocated to the Paging Channel (PCH). For example, withinavailable RB groups, RB groups may be sequentially selected from bothends of the system bandwidth until the necessary number of the resourceblocks of the selected RB groups have been selected, the necessarynumber of the resource blocks being determined based on the data size ofthe Paging Channel (PCH); and the selected RB groups are allocated tothe Paging Channel (PCH). Herein, the available RB group refers to theRB group which has not been determined to be allocated to any of theother channels at the timing when this process is performed.

When the Random Access Channel response (RACH response or Message2 inrandom access procedure) is transmitted via the sub-frame, the RB groupdetermined in advance is allocated to the RACH response. Otherwise, inaccordance with the data size of the RACH response or the number of userequipment (UE) terminals transmitting the RACH response, or inaccordance with available RB group, the RB group may be allocated to theRACH response. For example, within available RB groups, RB groups may besequentially selected from both ends of the system bandwidth until thenecessary number of the resource blocks of the selected RB groups havebeen selected, the necessary number of the resource blocks beingdetermined based on the data size of the RACH response; and the selectedRB groups are allocated to the RACH response. Herein, the available RBgroup refers to the RB group which has not been determined to beallocated to any of the other channels at the timing when this processis performed.

When the Dynamic Broadcast Channel (D-BCH) is transmitted via thesub-frame, the RB group determined in advance is allocated to theDynamic Broadcast Channel (D-BCH). Otherwise, in accordance with thedata size of the Dynamic Broadcast Channel (D-BCH) or the number of userequipment (UE) terminals transmitting the Dynamic Broadcast Channel(D-BCH), or in accordance with available RB group, the RB group may beallocated to the Dynamic Broadcast Channel (D-BCH). For example, withinavailable RB groups, RB groups may be sequentially selected from bothends of the system bandwidth until the necessary number of the resourceblocks of the selected RB groups have been selected, the necessarynumber of the resource blocks being determined based on the data size ofthe Dynamic Broadcast Channel (D-BCH); and the selected RB groups areallocated to the Dynamic Broadcast Channel (D-BCH). Herein, theavailable RB group refers to the RB group which has not been determinedto be allocated to any of the other channels at the timing when thisprocess is performed.

When the RACH message4 is transmitted via the sub-frame, the RB groupdetermined in advance is allocated to the RACH message4. Otherwise, inaccordance with the data size of the RACH message4 or the number of userequipment (UE) terminals transmitting the RACH message4, or inaccordance with available RB group, the RB group may be allocated to theRACH message4. For example, within available RB groups, RB groups may besequentially selected from both ends of the system bandwidth until thenecessary number of the resource blocks of the selected RB groups havebeen selected, the necessary number of the resource blocks beingdetermined based on the data size of the RACH message4; and the selectedRB groups are allocated to the RACH message4. Herein, the available RBgroup refers to the RB group which has not been determined to beallocated to any of the other channels at the timing when this processis performed.

In step S1104, the allocation of resource blocks to the MBMS channel(i.e., MCH) (RB allocation (process) for MCH) is performed. Namely whenthe MCH is transmitted via the sub-frame, the RB group determined inadvance is allocated to the MCH. Otherwise, in accordance with the datasize of the MCH or the number of user equipment (UE) terminalstransmitting the MCH, or in accordance with available RB group, the RBgroup may be allocated to the MCH. For example, within available RBgroups, RB groups may be sequentially selected from both ends of thesystem bandwidth until the necessary number of the resource blocks ofthe selected RB groups have been selected, the necessary number of theresource blocks being determined based on the data size of the MCH; andthe selected RB groups are allocated to the MCH. Herein, the availableRB group refers to the RB group which has not been determined to beallocated to any of the other channels at the timing when this processis performed.

Next, in step S1106, the allocation of resource blocks for PersistentScheduling (RB allocation (process) for Persistent Scheduling) isperformed. In step S1106, the Persistent Resources reserved in stepS1106 are allocated to the user equipment (UE) terminal having thedownlink shared channel (DL-SCH) to which the Persistent scheduling isapplied in the sub-frame.

However, with respect to the user equipment (UE) terminal to which thePersistent scheduling is applied in the sub-frame, the Schedulingcoefficient described in steps S1024 is calculated. When thetransmission resource are allocated for the Logical channel to which theDynamic scheduling is applied in the sub-frame, the base stationapparatus 200 releases the Persistent Resources and transmits the MACPDU (DL-SCH) to the user equipment (UE) terminal using Resourcesallocated for the Logical Channel to which the Dynamic scheduling isapplied. The method of multiplexing the data in the RLC buffer of theMAC control block and each Logical channel with the MAC PDU is describedbelow.

The transmission power of the downlink shared channel (DL-SCH) to whichthe Persistent scheduling is applied (total of transmission power of allthe resource elements (sub-carriers); absolute value; unit is W) isdefined as P_(persist). Herein, when there are two or more userequipment (UE) terminals having the downlink shared channel (DL-SCH) towhich the Persistent scheduling is applied, P_(persist) represents thetotal amount of the transmission power of the downlink shared channel(DL-SCH) of all the user equipment (UE) terminals, the Persistentscheduling being applied to the downlink shared channel (DL-SCH).

Next, in step S1108, a Calculation for Number of RBs for PDSCH (i.e., acalculation of the number of the resource blocks of the PhysicalDownlink Shared Channel (PDSCH)) is performed. More specifically, thenumber of the resource blocks “N_(dynamic) ^((RB))” that can beallocated to the Physical Downlink Shared Channel (PDSCH) using thefollowing formula (14) based on the maximum transmission power of thebase station apparatus 200 (hereinafter referred to as “P_(max)”: unit:W), transmission power of Synchronization signal “P_(SCH)”, transmissionpower of Primary Broadcast Channel (P-BCH) “P_(P-BCH)” transmissionpower of Paging Channel (PCH) “P_(PCH)”, transmission power of RandomAccess Channel (RACH) response “P_(RACHres)”, transmission power ofDynamic Broadcast Channel (D-BCH) “P_(D-BCH)”, transmission power ofRACH message4 “P_(RACHm4)”, transmission power of MBMS channel (MCH)“P_(MCH)”, transmission power per one resource block of downlink sharedchannel (DL-SCH) to which Persistent scheduling is applied“P_(persist)”, and transmission power per one resource block of downlinkshared channel (DL-SCH) to which Dynamic scheduling is applied“P_(dynamic)”. Herein, a symbol “N_(dynamic) ^((RB))” denotes the numberof resource blocks of the entire system bandwidth, and symbols“N_(P-BCH)”, “N_(SCH)”, “N_(PCH)”, “N_(RACHres)”, “N_(D-BCH)”,“N_(RACHm4)”, “N_(MCH)”, and “N_(persist)” denote the numbers ofresource blocks allocated to the P-BCH, Synchronization signal, PCH,RACH response, D-BCH, RACH message4, MCH, and the downlink sharedchannel (DL-SCH) to which the Persistent scheduling is applied,respectively in the sub-frame.

$\begin{matrix}{N_{dynamic}^{({RB})} = {\min\left( {{N_{system}^{({RB})} - N_{common} - N_{persist}},\left\lfloor \frac{P_{\max} - {\max\left( {P_{SCH},P_{P - {BCH}}} \right)} - P_{D - {BCH}} - P_{persist} - P_{PCH} - P_{RACHres} - P_{{RACHm}\; 4} - P_{MCH}}{P_{dynamic}^{({RB})}} \right\rfloor} \right)}} & (14)\end{matrix}$

When inequality N_(dynamic) ^((RB))<N_(system)^((RB))−N_(common)−N_(persist) is satisfied, the total transmissionpower value of the base station apparatus 200 is controlled so that thetotal transmission power value is equal to or less than the maximumtransmission power value of the base station apparatus 200 by preventingthe transmission using some RB group(s) among the RB groups other thanthe RB groups allocated to the P-BCH, PCH, RACH response, D-BCH, MCH,RACH message4 and downlink shared channel (DL-SCH) to which Persistentscheduling is applied. More specifically, until the transmission of“N_(system) ^((RB))−N_(common)−N_(persistent)−N_(dynamic) ^((RB))” ormore resource blocks is prohibited, the following process is performedto determine the RB group that is prevented from being transmitted. Inthis process, first, a RB group having the smallest number of resourceblocks is detected and the transmission of the detected RB group isprohibited. In this case, if there are two or more RB groups having thesmallest number of resource blocks, the transmission of the RB groups issequentially prohibited in the ascending order of the RB group number.The above process is repeated to sequentially determine the RB groupsthat are prevented from being transmitted. In the above example, aprocess is performed in which the transmission of the RB groups issequentially prohibited in the ascending order of the RB group number.However, alternatively, the transmission of the RB groups may besequentially prohibited in the descending order of the RB group number,the transmission of the RB groups may be sequentially prohibited fromthe RB groups at the center of the system bandwidth to the RB groups atthe both edges of the system bandwidth, the transmission of the RBgroups may be prohibited in any method other than the methods describedabove.

In step S1110, the value of “k” is set to 1 (one) (k=1).

Next, in step S1112, the RB Remaining Check process to determine whetherthere are any remaining resource blocks is performed.

More specifically, in step S1112, it is determined whether there is anyremaining RB group that can be allocated to the downlink shared channel(DL-SCH) to which Dynamic scheduling is applied. When determining thatthere is an allocatable RB group, the OK is returned. On the other hand,when determining that there is no allocatable RB group, the NG isreturned. When a result of the RB Remaining Check is NG (NG in stepS1112), the DL TFR Selection process is terminated.

The above-mentioned “RB group that can be allocated to the downlinkshared channel (DL-SCH) to which Dynamic scheduling is applied” refersto an RB group other than the RB groups having been allocated to any ofP-BCH, PCH, RACH response, D-BCH, RACH message4, MCH, DL-SCH to whichPersistent scheduling is applied, and DL-SCH to which Dynamic schedulingis applied and in which the TFR Selection process is already performed.Further, the number of resource blocks included in the “RB groups thatcan be applied to the downlink shared channel (DL-SCH) to which Dynamicscheduling is applied” is defined as N_(remain) ^((RB)).

In the above example, it is assumed that “RB group that can be allocatedto the downlink shared channel (DL-SCH) to which Dynamic scheduling isapplied” refers to an RB group other than the RB groups having beenallocated to any of P-BCH, PCH, RACH response, D-BCH, PACH message4,MCH, DL-SCH to which Persistent scheduling is applied, and DL-SCH towhich Dynamic scheduling is applied and in which the TFR Selectionprocess is already performed. However, alternatively, RB group that canbe allocated to the downlink shared channel (DL-SCH) to which Dynamicscheduling is applied” may be an RB group other than the RB groupshaving been allocated to any of Synchronization signal, P-BCH, PCH, RACHresponse, D-BCH, PACH message4, MCH, DL-SCH to which Persistentscheduling is applied, and DL-SCH to which Dynamic scheduling is appliedand in which the TFR Selection process is already performed.

On the other hand, when the result of the RB Remaining Check is OK (OKin step S1112), the process goes to step S1114.

Next, in step S1114, the DL TFR Selection (Downlink TFR Selection)process is performed.

More specifically, the transport format of “the user equipment (UE)terminal in which radio resources are allocated based on Dynamicscheduling” determined in step S1032 is determined and the allocation ofthe RB groups is performed.

The loop of steps S1110 through S1120 (see FIG. 11) based on a value of“k” is to be performed in accordance with the order of the selected“user equipment (UE) terminals in which radio resources are allocatedbased on Dynamic Scheduling” in step S1032.

In the DL TFR selection process, a CQI adjustment process is performed.With respect to the CQI used in the TFR Selection process, the followingprocesses are applied; the frequency direction regarding process, theOuter-loop type offset adjustment process, and the offset process basedon the priority level of the logical channel having the Highestpriority.

Next the frequency direction regarding process is described.

Based on the CQI values reported from the user equipment (UE) terminal,a CQI value of each RB group is calculated. In this case, if the CQIvalue across the system bandwidth (Wideband CQI) is reported but thereis no CQI value of UE selected sub-band in a user equipment (UE)terminal, it is assumed that the same value of the Wideband CQI is usedas the CQI value of UE selected sub-band in the user equipment (UE)terminal. In step S1020, with respect to the user equipment (UE)terminal in which the transmission type is determined as Distributed(transmission), it may be assumed that the CQI values of all the RBgroups are the same as the Wideband CQI (the CQI value across the systembandwidth).

In the following, when the CQI related to the entire system bandwidth isexpressed, an argument is described as “all”.

Next, the Outer-loop type offset adjustment process (CQI offsetadjustment) is described.

CQI_offset_(i) is adjusted like an Outer loop as shown in formula (8)described above based on the acknowledgement information (a result ofCRC check) of the downlink shared channel (DL-SCH) where the priorityclass of the logical channel having the Highest priority isX_(j,adjust). When the priority class of the logical channel having theHighest priority is other than X_(j,adjust), the Outer-loop type offsetadjustment process (in formula (8)) is not performed.

With respect to the user equipment (UE) terminal, when two or more MACPDU are to be transmitted within one sub-frame, the Outer-loop typeoffset adjustment process is performed on each of the two or more MACPDU. Herein, the transmission of two or more MAC PDU corresponds to thetransmission based on two or more codewards when MIMO is applied.

The CQI_offset_(i) is adjusted with respect to each user equipment (UE)terminal. Further, Priority class X_(j,adjust) as the target of the CQIoffset adjustment process is set via the external input interface (I/F).As described above, by performing the Outer-loop type offset adjustmentprocess with respect to one priority class having been determined inadvance instead of performing the Outer-loop type offset adjustmentprocess with respect to all the priority classes, it may become possibleto reduce the processing load of the base station apparatus. Forexample, as the Priority class X_(j,adjust), the Priority class to whichthe logical channel having the greatest transmission probability belongsis set.

Δ_(adj) ^((PC)) and BLER_(target) ^((PC)) may be configured to be setvia the external input interface (I/F). However, it is assumed that themaximum value of CQI_offset_(i) is defined as CQI_offset_(PC) ^((max)),and the minimum value of CQI_offset_(i) is defined as CQI_offset_(PC)^((min)). The maximum value CQI_offset_(PC) ^((max)) and the minimumvalue CQI_offset_(PC) ^((min)) of the CQI_offset_(i) are set via theexternal input interface (I/F). When the CQI_offset_(i) is fixed to themaximum value or the minimum value, the calculation of formula (8)described above is not performed.

Then, the value of CQI_offset_(i) is added to the value of CQI of eachRB group and a value of CQI related to the entire system bandwidth as apower offset value. A process of the formula (5) described above isperformed with respect to each sub-frame in which the DL TFR Selectionprocess is performed regardless of “whether the priority class of thelogical channel having the Highest priority is X_(j,adjust) in thesub-frame”.

Next, the offset process based on the priority level is described.

The CQI values of the corresponding RB groups and the CQI value relatedto the entire system bandwidth are adjusted using an offset value Δ_(PC)which is based on the priority level of the logical channel having theHighest priority. The Δ_(PC) may be set via the external input interface(I/F). The subscriber “pc” denotes Priority Class.CQI _(adjust)(i)=CQI _(adjust)(i)−Δ_(pc)

Next, a resource block group allocation (RB group allocation) isdescribed with reference to FIG. 12. By performing the process below,the RB group is allocated to kth user equipment (excluding PCH and RACHresponse) in which radio resources are allocated based on the DynamicScheduling. FIG. 6 schematically shows a DL_TF_Related_table and a casewhere CQI=1 as an example.

Process

The following parameters are set in step S1202.

N_(remain) ^((RB)): the number of remaining resource blocks (Number ofRemaining RBs)

N_(capability): the maximum RB number

N_(max,bit): the maximum data size (Payload size) determined based on UEcategory

Herein, N_(capability) may be set as a parameter in the apparatus or asa parameter to be input from an upper node, or may be set based on theinformation included in “UE capability” reported from the user equipment(UE) terminal.

Further, in a case where an instruction to reduce the data rate isissued from the user equipment (UE) terminal, the N_(capability) may becalculated based on the following formula.N _(capability) =N _(capability)*α

Herein, a symbol a may denote a ratio against the maximum receivablethroughput of the user equipment (UE) terminal. For example, when thebase station apparatus 200 receives an instruction (request) from theuser equipment (UE) terminal to transmit the downlink shared channel(DL-SCH) at the rate of 80% or less of the maximum receivable throughputof the user equipment (UE) terminal, α may be set to 0.8 (α=0.8).Further, as the method of reporting the instruction (request) by theuser equipment (UE) terminal, in a case where data rate is required tobe reduced, the ratio against the maximum receivable throughput of theuser equipment (UE) terminal or an absolute throughput value may bereported. In any case, the base station apparatus 200 may calculate thevalue of α by deriving the ratio against the maximum receivablethroughput of the user equipment (UE) terminal from an instruction fromthe user equipment (UE) terminal to perform the calculation of the aboveformula.

Further, in a case where an instruction to reduce the data rate isissued from the user equipment (UE) terminal, the N_(max,bit) may becalculated based on the following formula.N _(max,bit) =N _(max,bit)*α

Herein, a symbol α may denote a ratio against the maximum receivablethroughput of the user equipment (UE) terminal. For example, when thebase station apparatus 200 receives an instruction (request) from theuser equipment (UE) terminal to transmit the downlink shared channel(DL-SCH) at the rate of 80% or less of the maximum receivable throughputof the user equipment (UE) terminal, α may be set to 0.8 (α=0.8).Further, as the method of reporting the instruction (request) by theuser equipment (UE) terminal, in a case where data rate is required tobe reduced, the ratio against the maximum receivable throughput of theuser equipment (UE) terminal or an absolute throughput value may bereported. In any case, the base station apparatus 200 may calculate thevalue of α by deriving the ratio against the maximum receivablethroughput of the user equipment (UE) terminal from an instruction fromthe user equipment (UE) terminal to perform the calculation of the aboveformula.

Next, in step S1204, the number “N_(allocated) ^((RB))” of resourceblocks allocatable to the user equipment (UE) terminal is calculated.N _(remain) ^((UE))=min(N _(DL-SCH) −k+1,N _(capability))

Based on this formula, it may become possible to control the number ofresource blocks allocated to the user equipment (UE) terminal to beequal to or less than N_(capability). Herein, min(A,B) refers to afunction to output A or B whichever is smaller.

$\begin{matrix}{N_{allocated}^{({RB})} = {\min\left( {\left\lceil \frac{N_{remain}^{({RB})}}{N_{remain}^{({UE})}} \right\rceil,N_{capability}} \right)}} & (15)\end{matrix}$

In step S1206, it is determined whether the downlink transmission typeis Localized or Distributed.

When determining that the downlink transmission type is Distributed(result of determination in step S1206 is Distributed), the process goesto step S1208. In step S1208, RB groups are selected so that theallocated frequency resources can be discretely distributed within thesystem bandwidth until the number of the allocated resource blocksexceeds N_(allocated) ^((RB)) or more. For example, the RB groups may beselected so that the allocated frequency resources can be discretelydistributed within the system bandwidth by alternately assigning(selecting) the RB blocks from both ends of the system bandwidth.Otherwise, the RB groups may be selected so that the allocated frequencyresources can be discretely distributed within the system bandwidth byalternately selecting from both the RB group having the largest RB groupnumber and the RB group having the smallest RB group number.

When determining that the downlink transmission type is not Distributed(i.e., Localized; result of determination in step S1206 is Localized),the process goes to step S1210. In step S1210, the RB groups aresequentially allocated to the user equipment (UE) terminal in thedescending order of the values of CQI_(adjusted) until the number ofresource blocks allocated to the user equipment (UE) terminal reachesN_(allocated) ^((RB)) or more.

Before determining whether the downlink transmission type is Localizedor Distributed in step S1206, a method of allocating the RB groups tothe user equipment (UE) terminal may be determined based on the pathloss value between the user equipment (UE) terminal and the base stationapparatus 200. For example, after a threshold value Threshold_(DL,PL) isdefined, when determining that the path loss value is greater than thethreshold value Threshold_(DL,PL), the RB groups are sequentiallyallocated to the user equipment (UE) terminal in the descending order ofthe frequency values of the RB groups until the number of the resourceblocks allocated to the user equipment (UE) terminal reachesN_(allocated) ^((RB)) or more. On the other hand, when determining thatthe path loss value is equal to or less than the threshold valueThreshold_(DL,PL), the above determination whether the downlinktransmission type is Localized or Distributed is performed, and theallocation of the RB groups may be performed based on the result of thedetermination. Otherwise, in the above process, when determining thatthe path loss values is equal to or less than the threshold valueThreshold_(DL,PL), without determining whether the downlink transmissiontype is Localized or Distributed, the RB groups may be sequentiallyallocated to the user equipment (UE) terminal in the ascending order ofthe frequency values of the RB groups. Further, the path loss value maybe calculated based on the UE Power Headroom and uplink shared channelreported from the user equipment (UE) terminal and the received qualityof the Sounding reference signal or based on the path loss valuereported from the user equipment (UE) terminal. In this case, the pathloss value calculated from the UE Power Headroom, uplink shared channel,or the received quality of the Sounding reference signal reported fromthe user equipment (UE) terminal corresponds to the uplink path lossvalue, and the path loss value reported from the user equipment (UE)terminal corresponds to the downlink path loss value.

For example, in an LTE system employing the FDD (Frequency DivisionDuplex) scheme is employed, the uplink transmission signal in the userequipment (UE) terminal may become an interference signal to thedownlink reception signal; and as a result, the quality of the downlinkreception signal may be degraded. Generally, in user equipment (UE)terminals, there is a functional section called a Duplexer, whichprevents the leakage of the uplink transmission signal into thefunctional section receiving a downlink signal and performing thedemodulation and decoding. However, the leakage cannot be fullyprevented. FIG. 14 schematically shows the mechanism of interference inthe user equipment (UE) terminal. As shown in FIG. 14, the transmissionsignal generated in the transmission section is leaked into thereceiving section without the power of the transmission signal beingfully reduced in the Duplexer, and the leaked transmission signal maybecome an interference signal which degrades the quality of the receivedsignal.

The more separated the difference is between the frequency of the uplinktransmission signal and the frequency of the downlink reception signal,or the smaller the transmission power of the uplink transmission signalis, the smaller the leakage becomes. Further, in uplink, the larger thepath loss value is, the larger the transmission power becomes.Therefore, when the path loss value is relatively large, by allocatingthe frequency resource having a higher frequency, it may become possibleto reduce the interference of the uplink transmission signal to thedownlink reception signal. FIG. 15 schematically shows an effect causedby reducing the interference of the uplink transmission signal to thedownlink reception signal. As shown in FIG. 15, when path loss value isrelatively large, a UL frequency band and a DL frequency band is moreseparated from each other. Namely when the path loss value is relativelylarge, a frequency band allocated to the DL transmission signal to theuser equipment (UE) terminal is more separated from the UL transmissionbandwidth. On the other hand, when the path loss value is relativelysmall, the difference between UL frequency band and DL frequency band isreduced. Namely when the path loss value is relatively small, afrequency band allocated to the DL transmission signal to the userequipment (UE) terminal is set closer to the UL transmission bandwidth.This is because the UL transmission power is small which is less likelyto cause the interference problem due to the uplink signal.

In the above example, it is assumed that the UL frequency is lower thanthe DL frequency. Therefore, in a case where the UL frequency is higherthen the DL frequency, in an opposite manner, when the path loss valueis greater than the threshold value Threshold_(DL,PL), a process isperformed in which the RB groups are sequentially allocated to the userequipment (UE) terminal in the ascending order of the frequencies of theRB groups until the number of the resource blocks allocated to the userequipment (UE) terminal reaches the N_(allocated) ^((RB)) or more.

Further, in the above process, the order of performing the steps S1110through S1120 of the user equipment (UE) terminals (i.e., order of “k”loop) is determined in step S1032 in which the order is determined basedon the order of “allocating the radio resources to the user equipment(UE) terminals in accordance with the Dynamic scheduling”. Howeveralternatively, the order of performing the steps S1110 through S1120 ofthe user equipment (UE) terminals (i.e., order of “k” loop) may bedetermined in accordance with the descending order of the path lossvalues. More specifically, the process of steps S1100 through S1120 issequentially performed in the descending order of the path loss valuesof the user equipment (UE) terminals. In this case, certainly, thefrequency resources are sequentially allocated to the user equipment(UE) terminals in the descending order of the frequencies of thefrequency resources in a manner so that the larger the path loss valueof the user equipment (UE) terminal is, the more separated frequencyresource from the uplink transmission frequency is allocated, i.e., thehigher frequency of the frequency resource is allocated to the userequipment (UE) terminal. As a result, it may become possible to improvethe effect of reducing the interference of the uplink transmissionsignal to the downlink reception signal.

In the following, the RB group determined “to be allocated to the userequipment (UE) terminal” in the processes of steps S1208 and S1210 iscalled “Temporary RB group”.

In step S1212, it is determined whether the logical channel having theHighest priority includes retransmittable data.

When determining that the logical channel having the Highest priorityhas retransmittable data (result of the determination in step S1212 isYES), the process goes to step S1214. On the other hand, whendetermining that the logical channel having the Highest priority has noretransmittable data (result of the determination in step S1212 is NO),the process goes to step S1213.

In step S1213, it is determined whether there is an HARQ process for anew transmission. When determining that there is no HARQ process for anew transmission (result of the determination in step S1213 is NO), theprocess goes to step S1215.

In step S1214, among the retransmittable data (MAC PDU), the data (MACPDU) including RLC SDU having the maximum “buffer residence time of theRLC SDU” of the logical channel having the Highest priority are selectedas the MAC PDU to be transmitted via the subframe. Namely the data (MACPDU) including RLC SDU having the maximum “buffer residence time of theRLC SDU” of the logical channel having the Highest priority aretransmitted. Herein, the definition of the “buffer residence time of theRLC SDU” is the same as that of the RLC SDU buffer residence timedescribed in No. 5 of Table 7.

In step S1215, among the retransmittable data (MAC PDU), retransmissiondata (MAC PDU) having the highest priority level are transmitted.Herein, the priority level refers to the priority level of the Logicalchannel having the Highest priority among the Logical Channelsmultiplexed to the retransmission data (MAC PDU). Further, when thereare plural retransmission data (MAC PDU) having the highest prioritylevel, the data (MAC PDU) including the RLC SDU having the maximum“buffer residence time of the RLC SDU” of the logical channel having theHighest priority are transmitted. Herein, the definition of the “bufferresidence time of the RLC SDU” is the same as that of the RLC SDU bufferresidence time described in No. 5 of Table 7.

Further, in step S1216, the RB group and the modulation scheme to beused for the transmission of the sub-frame are determined. It is assumedthat the RB group to be used for the transmission of the sub-frame isthe same as the Temporary RB group. It is also assumed that themodulation scheme is the same as that in the initial transmission. Inthe above example, a case is described where the RB groups used for thedata transmission correspond to the Temporary RB groups. However,alternatively, when the number of resource blocks included in the RBgroups used for the data transmission is greater than the number ofresource blocks allocated in the initial transmission, a process may beperformed in which some of the RB groups used for the transmission ofthe sub-frame are not allocated until the number of resource blocksreaches the number of resource blocks allocated in the initialtransmission.

Further, instead of assuming that the RB group to be used for thetransmission of the sub-frame is the same as the Temporary RB group,based on the number of resource blocks in the RB groups, the number ofthe resource blocks in the RB groups may be reduced. Specifically, whenthe number of resource blocks in the Temporary RB groups is greater thantwo times the number of the resource blocks in the RB groups in theinitial transmission, the number of the resource blocks of the TemporaryRB groups may be reduced so that the number of the resource blocks ofthe Temporary RB groups is less than two times the resource blocks inthe RB groups in the initial transmission. As the method of reducing theresource block numbers, the same method as described in steps S1224 orS1232 may be used. In the above example, two times is used. However, anyother factor such as one time, three times, or the like indicating otherthan two times may also be used.

On the other hand, when determining that there is the HARQ process for anew transmission (result of the determination in step S1213 is YES), theprocess goes to step S1218.

In step S1218, a CQI value “CQI_(TFR)” in the Temporary RB group iscalculated as described below.

When determining that the downlink transmission type is Distributed, itis assumed that CQI_(TFR) is defined as CQI_(adjusted) (all)(CQI_(TFR)=CQI_(adjusted) (all)). On the other hand, when determiningthat the downlink transmission type is not Distributed (i.e.,Localized), it is assumed that CQI_(TFR) is obtained by true-valueaveraging the CQI_(adjusted) with respect each RB group in the TemporaryRB group across the bandwidth of the Temporary RB group (the averagingis required to be performed by considering (the difference of) thenumber of resource blocks of each RB groups).

Next, in step S1220, the data size (“Size”) and the modulation scheme(“Modulation”) of the downlink shared channel (DL-SCH) are determined byreferring to TF_related_table using the number (RB_available) ofresource blocks in the Temporary RB group and CQI_(TFR) as arguments.Size=DL_Table_(—) TF_SIZE(RB_available,└CQI _(TFR)┘)Modulation=DL_Table_(—) TF_Mod(RB_available,└CQI _(TFR)┘)  (16)

In step S1222, it is determined whether inequality Size>N_(max,bit) issatisfied (correct). When determining that Size>N_(max,bit) is satisfied(result of determination in step S1222 is YES), the process goes to stepS1224, in which the number of resource blocks (RB available) is reduceduntil inequality Size≦N_(max,bit) is satisfied. Namely the number ofresource blocks NUM_(RB) to be allocated is recalculated by referring tothe TF_related_table using N_(max,bit) and CQI_(TFR) as arguments.Num_(RB) =DL_Table_(—) TF _(—) RB(N _(max,bit) ,└CQI _(TFR)┘)  (17)

Then, when determining that the downlink transmission type isDistributed, RB groups in the Temporary RB group are removed byrepeating the following process until the number of resource blocks inthe RB group to be used for the transmission is equal to or less thanNUM_(RB) (removed RB groups are used as (k+1)th radio resource orlater).

Process: The RB groups are alternately removed from both of the RB grouphaving the smallest RB group Number and the RB group having the greatestRB group Number.

The number of resource blocks in the Temporary RB group after the aboveprocess is intended to be performed is defined as Num_(RB). The aboveprocess is performed so that the remaining RB groups after the removalof the RB groups can be discretely distributed in the system bandwidth.

On the other hand, when determining that the downlink transmission typeis Localized, RB groups in the Temporary RB group are removed byrepeating the following process until the number of resource blocks inthe RB group to be used for the transmission is equal to or less thanNUM_(RB) (removed RB groups are used as (k+1)th radio resource orlater).

Process: The RB group having the smallest CQI_(adjusted) is removed.When there are two or more RB groups having the smallest CQI_(adjusted),the RB groups are sequentially removed in the ascending order of thenumber of resource blocks in the RB groups. When there are two or moreRB groups having the smallest CQI_(adjusted) and having the smallestnumber of resource blocks, the RB groups are sequentially removed in thedescending order of the RB group numbers of the RB groups.

The Temporary RB group after the above process is performed is treatedas the Temporary RB group in the following process; and the number ofthe resource blocks in the Temporary RB group after the above process isdefined as Num_(RB). Further, the data size (“Size”) and the modulationscheme (“Modulation”) of the downlink shared channel (DL-SCH) aredetermined again by referring to TF_related_table using the number(RB_available) of resource blocks in the Temporary RB group andCQI_(TFR) as arguments.Size=DL_Table_(—) TF_SIZE(RB_available,└CQI _(TFR)┘)Modulation=DL_Table_(—) TF_Mod(RB_available,└CQI _(TFR)┘)  (18)

After step S1224, the process goes to step S1226.

On the other hand, when determining that Size≦N_(max,bit) is satisfied(result of determination in step S1222 is NO), the process goes to stepS1226.

Next, in step S1226, it is determined whether there are sufficient datain the RLC Buffer.

When determining that there are sufficient data in the RLC Buffer(result of determination in steps S1226 is YES), the process goes tostep S1228, in which, by the following procedures, the controlinformation of the MAC layer and the data of all logical channels in theRLC Buffer are multiplexed with the MAC PDU having the Size.

Step 1: First, when there is control information of the MAC layer, thecontrol information of the MAC layer is multiplexed with the highestpriority.

Step 2: Next, the data in the RLC Buffer are sequentially extracted andmultiplexed in the descending order of the priority levels of thelogical channels. When there are two or more logical channels having thesame priority level, if there are a DCCH, the DDCH is treated with thehighest priority, and if there is no DDCH, the data in the RLC buffermay be sequentially extracted from the logical channels in any order. Asa method of selecting the logical channel in any order, the Round-Robinmethod may be used.

Next, in step S1230, the RB group, the modulation scheme, and thepayload size to be used for the transmission of the sub-frame aredetermined. Specifically, the RB group to be used for the datatransmission is same as the Temporary RB group. The modulation scheme tobe used for the data transmission is the same as the Modulation. Thepayload size is the same as the Size.

On the other hand, when determining that there are no sufficient data inthe RLC Buffer (result of determination in steps S1226 is NO), theprocess goes to step S1232, in which, until inequality Size≦Size_(all)is satisfied, the number of resource blocks to be allocated is reduced.Herein, the symbol Size_(all) denotes total size of the data in the RLCbuffer of the MAC control block and all the Logical channels. Theprocessing method is described in more detail below.

First, the number NUM_(RB) of resource blocks to be allocated isrecalculated by referring to the TF_related_table using the total size“Size_(all)” of the data in the RLC buffer of the MAC control block andall the logical channels and the “CQI_(TFR)” as arguments.Num_(RB) =DL_Table_(—) TF _(—) RB(Size_(all) ,└CQI _(TFR)┘)  (19)

When determining that the downlink transmission type is Distributed, theRB groups in the Temporary RB group are removed by repeating thefollowing process as long as the number of RB groups to be used fortransmission is equal to or greater than the NUM_(RB).

Process: Among the RB groups in the Temporary RB group, the RB groupsare sequentially and alternately removed from both the RB group havingthe greatest RB group number and the RB group having the smallest RBgroup number.

The Temporary RB group after the above process is used as the TemporaryRB group in the following process. Further, the number of resourceblocks in the Temporary RB group is defined as Num_(RB,F).

When determining that the downlink transmission type is not Distributed,namely when determining that the downlink transmission type isLocalized, the RB groups in the Temporary RB group are removed byrepeating the following process as long as the number of RB groups to beused for transmission is equal to or greater than the NUM_(RB).

Process: The RB groups are sequentially removed in the ascending orderof the CQI_(adjusted) values of the RB groups. When there are two ormore RB groups having the smallest CQI_(adjusted) value, the RB groupsare sequentially removed in the ascending order of the number ofresource blocks of the RB groups. When there are two or more RB groupshaving the smallest CQI_(adjusted) value and having the smallest numberof resource blocks, the RB groups are sequentially removed in thedescending order of the RB group numbers of the RB groups.

The Temporary RB group after the above process is used as the TemporaryRB group in the following process. Further, the number of resourceblocks in the Temporary RB group is defined as Num_(RB,F).

The removed RB groups in the above processes are used as (k+1)th radioresource or later.

Further, the data size (“Size”) and the modulation scheme (“Modulation”)of the downlink shared channel (DL-SCH) are determined again byreferring to TF_related_table using the number (Num_(RB,F)) of resourceblocks in the Temporary RB group and CQI_(TFR) as arguments.Size=DL_Table_(—) TF_SIZE(Num_(RB,F) ,└CQI _(TFR)┘)Modulation=DL_Table_(—) TF_Mod(Num_(RB,F) ,└CQI _(TFR)┘)  (20)

Further, in step S1234, the control information of the MAC layer and thedata of all logical channels in the RLC Buffer are multiplexed with theMAC PDU having the Size.

Next, in step S1230, the RB group, the modulation scheme, and thepayload size to be used for the transmission of the sub-frame aredetermined. Namely the RB group to be used for the data transmission isthe same as the Temporary RB group. The modulation scheme to be used forthe data transmission is the same as the Modulation. The payload size isthe same as the Size.

The RLC buffer described in the above examples is generally a databuffer. Further, the same above processes may be performed on not theRLC buffer but the PDCP buffer.

In step S1116, the RV selection (Redundancy Version Selection) processis performed.

In step S1118, the value of “k” may be incremented, and in step S1120,it may be determined whether the value of “k” is equal to or less thanN_(DL-SCH) when determining that the value of “k” is equal to or lessthan N_(DL-SCH) (YES in step S1120), the process may go back to stepS1112. On the other hand, when determining that the value of “k” is notequal to or less than N_(DL-SCH) (NO in step S1120), the process mayterminate.

Next, the base station apparatus 200 according to an embodiment of thepresent invention is described with reference to FIG. 13.

As shown in FIG. 13, the base station apparatus 200 according to anembodiment of the present invention includes a layer 1 processingsection 252, a user equipment status management section 254, ascheduling coefficient counting section 256, a UE selection section 258,a TFR (Transport Format Resource block) Selection section 268, an MACcontrol signal generation section 260, a common channel/MCH resourcemanagement section 262, a frequency resource management section 264, apersistent resource management section 266, an HARQ control section 270,and an RLC/PDCP processing section 272. The HARQ control section 270includes HARQ₁ control section 270, HARQ₂ control section and HARQcontrol section 270 corresponding to UE(user equipment terminal)#1,UE#2, . . . , and UE#n, respectively. The RLC/PDCP processing section272 includes RLC Bufs 2722 _(1,1) through 2722 _(1,k) for logicalchannels #1 through #k of UE#1, RLC Bufs 2722 _(2,1) through 2722 _(2,k)for logical channels #1 through #k of UE#2, . . . , RLC Bufs 2722 _(n,1)through 2722 _(n,k) for logical channels #1 through #k of UE#n,respectively.

In FIG. 13, the base station apparatus 200 includes one HARQ controlsection with respect to each UE (i.e., n×HARQ for n×UE). Howeveralternatively, the base station apparatus 200 may include only one HARQcontrol section for all or plural UEs. Further, it is not alwaysnecessary to provide one RLC BUf for each logical channel of each UE.Alternatively, one RLC Buf may be provided for one UE or all UEs.

The layer 1 processing section 252 performs processes related to thelayer 1. More specifically, the layer 1 processing section 252 performs,for example, a channel coding process and an IFFT process on the sharedchannel transmitted in downlink and a reception process such as an FFTprocess and a channel decoding process on the shared channel transmittedin uplink. The shared channel transmitted in uplink refers to, forexample, a shared channel to which the Dynamic Scheduling is applied anda shared channel to which the Persistent Scheduling is applied.

Further, the layer 1 processing section 252 performs the transmission ofthe Downlink Scheduling Information and the Uplink Scheduling Grant, theDownlink Scheduling Information being control information for thedownlink shared channel (DL-SCH), the Uplink Scheduling Grant beingcontrol information for the uplink shared channel (UL-SCH).

Further, the layer 1 processing section 252 performs the reception ofcontrol information transmitted in uplink, i.e., the control informationincluding the CQI (Channel Quality Information) and the acknowledgementinformation with respect to the downlink shared channel. Such CQI andthe acknowledgement information are transmitted to the user equipmentstatus management section 254.

Further, the layer 1 processing section 252 detects uplinksynchronization status based on the Sounding reference signaltransmitted in uplink and the CQI signal and reports the detectionresult to the user equipment status management section 254.

Further, the layer 1 processing section 252 may estimate uplinkreception timings based on the Sounding reference signal transmitted inuplink and the CQI signal and reports the estimation result of theuplink reception timings to the MAC control signal generation section260 via, for example, the user equipment status management section 254.

Further, the layer 1 processing section 252 is connected to a radiointerface. More specifically, in downlink, the baseband signal generatedin the layer 1 processing section 252 is converted into a signal inradio frequency band. Then the converted signal is amplified in theamplifier and transmitted to user equipment (UE) via an antenna. On theother hand, in uplink, a radio-frequency signal received by the antennais amplified in the amplifier, frequency-converted into a basebandsignal, and is input to the layer 1 processing section 252.

The user equipment status management section 254 performs statusmanagement of the user equipment (UE) terminals. For example, theequipment status management section 254 performs status management ofHARQ Entity, management and control of Mobility of UE, manages DRXstatus and uplink synchronization, whether Persistent scheduling is tobe applied, whether MAC Control Block is to be transmitted, the downlinktransmission status, and a buffer status. Further, in step S1024, theequipment status management section 254 calculates metrics necessary forthe calculation of the Scheduling Coefficient and determines whether theScheduling Coefficient is to be calculated. Namely the equipment statusmanagement section 254 performs processes in steps S1004 through S1022in FIG. 10.

The Mobility of the UE described above refers to a handover switching acell to which the UE is to be communicated, the handover includinghandover between the same frequency, between different frequencies, andbetween different systems. In cases of the handover between thedifferent frequencies or between different systems, the management andcontrol of the Management Gap is included in the management and controlof Mobility of UE.

Further, the equipment status management section 254 performs theprocesses of steps S902, S904, and S906. More specifically, theequipment status management section 254 sets the maximum multiplexingnumber per a sub-frame with respect to the DL MAC of the sub-frame,counts the numbers of MCH, D-BCH, PCH, RACH response and RACH message4in the sub-frame.

The scheduling coefficient counting section 256 performs the processesof steps S1002 and S1024 through S1032 in FIG. 10. More specifically,the scheduling coefficient counting section 256 calculates thescheduling coefficients of the user equipment (UE) terminals in thesub-frame (see FIG. 11). On the other hand, the UE selection section 258selects the user equipment (UE) terminals to which radio resources areallocated based on the Dynamic scheduling based on the calculatedScheduling Coefficients. The UE selection section 258 reports the number“N_(DL-SCH)” of the user equipment (UE) terminals to which radioresources are allocated based on the Dynamic scheduling to the TFR(Transport Format Resource block) Selection section 268.

The TFR Selection section 268 performs the processes of steps S1110,S1112, S1114, S1116, and S1120. More specifically, the TFR Selectionsection 268 determines the transmission formats and allocates radioresources related to the downlink shared channel (DL-SCH) to which theDynamic Scheduling is applied. The information of the transmissionformats and radio resources related to the downlink shared channel(DL-SCH) to which the Dynamic Scheduling is applied determined by theTFR Selection section 268 is transmitted to the layer 1 processingsection 252 to be used for the transmission processes of the DLScheduling Information and the downlink shared channel (DL-SCH) in thelayer 1 processing section 252.

The common channel/MCH resource management section 262 determines thetransmission formats and allocates the radio resources for the MCH andcommon channels such as Synchronization channel (SCH), Primary BroadcastChannel (P-BCH), Dynamic Broadcast Channel (D-BCH), Paging Channel(PCH), Random Access Channel response (RACH response), and PACHmessage4. The common channel/MCH resource management section 262 reportsthe frequency resources among the radio resources to the frequencyresource management section 264. The information of the transmissionformats and allocated radio resources determined by the commonchannel/MCH resource management section 262 is transmitted to the layer1 processing section 252 via the frequency resource management section264 and the TFR Selection section 268, so that layer 1 processes of theMCH and the Common Channels are performed in the layer 1 processingsection 252.

The frequency resource management section 264 is connected to the TFRSelection section 268, the common channel/MCH resource managementsection 262, and the persistent resource management section 26 andperforms the management of the frequency resources. More specifically,the frequency resource management section 264 monitors remainingfrequency resources usable for the downlink shared channel (Dl-SCH) towhich Dynamic Scheduling is applied and provides information necessaryfor the process of step S1110 to the TFR Selection section 268.

The persistent resource management section 266 performs the statusmanagement of the downlink shared channel (DL-SCH) to which thePersistent Scheduling is applied and manages the radio resources. Morespecifically, the persistent resource management section 266 determinesthe transmission formats related to the downlink shared channel (DL-SCH)to which the Persistent Scheduling is applied and manages the radioresources. Further, the persistent resource management section 266reports the frequency resources among the radio resources to thefrequency resource management section 264. The information of thetransmission formats and allocated radio resources determined bypersistent resource management section 266 is transmitted to the layer 1processing section 252 via the frequency resource management section 264and the TFR Selection section 268, so that the process of the layer 1 ofdownlink shared channel (DL-SCH) to which the Persistent Scheduling isapplied is performed in the layer 1 processing section 252.

Further, the persistent resource management section 266 sends theinformation necessary to perform the processes of steps S1012 throughS1016 performed in the equipment status management section 254 to theequipment status management section 254.

The MAC control signal generation section 260 determines whether the MACcontrol signal is to be transmitted to each user equipment (UE)terminal, and when determining that the MAC control signal is to betransmitted, reports the result of determination to the equipment statusmanagement section 254. Further, when the MAC control signal is to beactually mapped, the MAC control signal generation section 260 sends theMAC control signal to the TFR Selection section 268.

The MAC control signal includes, for example, a control signalinstructing the timing advance for adjusting the transmission timing ofthe uplink signal and the establishment of the uplink synchronizationand a control signal instructing to go into DRX mode. Whether each ofthe control signals is to be transmitted is determined based on theinformation from the equipment status management section 254 or thelayer 1 processing section 252.

The HARQ_(n) control section 270 performs the control with respect tothe HARQ of each user equipment (UE) terminal.

The RLC/PDCP processing section 272 performs the control of the RLClayer and the PDCP layer of each user equipment (UE) terminal. Further,the RLC/PDCP processing section 272 includes RLC Buf2721 _(n,k) which isthe RLC Buffer related to the logical channel #k of UE #n so as tobuffer the data of the PDCP layer to be transmitted in downlink.

In the above example, the RLC BUf2721 _(n,k) buffers the data of the RLClayer. However alternatively, the RLC BUf2721 _(n,k) may buffer the dataof the RLC layer and the PDCP layer as well.

Namely, the data transmitted via the downlink shared channel (DL-SCH) inthe sub-frame are extracted by the RLC BUf2721 _(n,k) in the RLC/PDCPprocessing section 272, HARQ-processed in the HARQ_(n) control section270, and transmitted to the layer 1 processing section 252 via the UEselection section 258 and the TFR Selection section 268, so that thetransmission processes such as coding, IFFT, and the like in the layer 1processing section 252.

The present invention is described above by referring to specificembodiments. However, it should not be understood that the descriptionsand figures constituting the parts of the disclosure limit the presentinvention. Based on the disclosure, a person skilled in the art maythink of examples of various modifications, transformations,alterations, operational technique, and the like.

For example, in the above embodiments, a system in which Evolved UTRAand UTRAN (a.k.a. Long term Evolution or Super 3G) is applied isdescribed. However, a mobile station (user equipment (UE) terminal), abase station apparatus, a mobile communication system, and communicationcontrol method according to an embodiment of the present invention mayalso be applied to any other system capable of communicating using theshared channel.

Namely obviously, the present invention includes various embodiments notdescribed herein. Therefore, a technical scope of the present inventionis defined only by the invention specifying matters according toadequate scopes of the claims based on the descriptions.

For explanation purpose, plural embodiments are separately described.However, such separation of the embodiments is not essential to thepresent invention, and two or more embodiments may be used on an asneeded basis.

Further, for explanation purpose, specific values are used to promoteunderstanding the present invention. However, unless otherwisedescribed, the values are for illustrative purpose only and any othersuitable values may be used.

The present invention is described above by referring to specificembodiments. However, a person skilled in the art may understand thatthe above embodiments are described for illustrative purpose only andmay think of examples of various modifications, transformations,alterations, changes, and the like. For illustrative purposes, theapparatus according to an embodiment of the present invention isdescribed with reference to the functional block diagram. However, suchan apparatus may be provided by hardware, software, or a combinationthereof. The present invention is not limited to the embodimentdescribed above, and various modifications, transformations, alteration,exchanges, and the like may be made without departing from the scope andspirit from the present invention.

The present international application claims priority from JapanesePatent Application Nos. 2007-052115 filed on Mar. 1, 2007, 2007-161938filed on Jun. 19, 2007, and 2007-329024 filed on Dec. 20, 2007, theentire contents of which Japanese Patent Application Nos. 2007-052115,2007-161938, and 2007-329024 are hereby incorporated herein byreference.

The invention claimed is:
 1. A base station apparatus capable ofcommunicating with a user equipment terminal using a downlink sharedchannel, the base station apparatus comprising: a selection unitconfigured to select a user equipment terminal transmitting a sharedchannel from among user equipment terminals other than: a user equipmentterminal in which a time frame to transmit the shared channel or a timeframe to receive acknowledgement information with respect to the sharedchannel overlaps with a time interval when cells are measured, the celloperating at a different frequency, a user equipment terminal in sleepmode of discontinuous reception mode, a user equipment terminal that hasnot received radio quality information, and a user equipment terminalhaving no data to be transmitted; and a transmission unit configured totransmit the shared channel to the user equipment terminal selected bythe selection unit.
 2. A base station apparatus capable of communicatingwith a user equipment terminal using a downlink shared channel, the basestation apparatus comprising: a selection unit configured to select auser equipment terminal transmitting a shared channel from among userequipment terminals other than a user equipment terminal in which a timeframe to transmit the shared channel or a time frame to receiveacknowledgement information with respect to the shared channel overlapswith a time interval when cells are measured, the cell operating at adifferent frequency; and a transmission unit configured to transmit theshared channel to the user equipment terminal selected by the selectionunit.
 3. The base station apparatus according to claim 1, wherein uponinstructing a handover to the user equipment terminal, the selectionunit takes only control information into consideration as data to betransmitted to the user equipment terminal and does not take any dataother than the control information into consideration.
 4. The basestation apparatus according to claim 1, wherein with respect to a userequipment terminal starting communication with the base stationapparatus due to a handover operation, the selection unit assumes thatthere are no data to be transmitted to the user equipment terminal untila data transmission from a handover source base station apparatus iscompleted and a Status Report of a PDCP (packet data convergenceprotocol) layer is received.
 5. The base station apparatus according toclaim 1, wherein with respect to data in which a transmission window ofan RLC (Radio Link Control) layer of the user equipment terminal is install mode, the selection unit assumes that there are no data to betransmitted.
 6. The base station apparatus according to claim 1, whereinwhile an uplink synchronization status with respect to the userequipment terminal is not established, the selection unit takes onlycontrol information into consideration as data to be transmitted to theuser equipment terminal and does not take any data other than thecontrol information into consideration.
 7. A base station apparatuscapable of communicating with a user equipment terminal using uplink anddownlink shared channels, the base station apparatus comprising: aselection unit configured to select a user equipment terminaltransmitting a shared channel from among user equipment terminals otherthan: a user equipment terminal in which a time frame to transmit thedownlink shared channel overlaps with a time frame to transmit theuplink shared channel, a user equipment terminal in which the time frameto transmit the downlink shared channel overlaps with a time frame totransmit, in uplink, to a sounding reference signal, downlink radioquality information, a scheduling request signal, or a random accesschannel, a user equipment terminal in which the time frame to transmitthe downlink shared channel overlaps with a time frame to transmitacknowledgement information (ACK/NACK) with respect to the downlinkshared channel, a user equipment terminal in which the time frame totransmit acknowledgement information with respect to the downlink sharedchannel overlaps with a time frame to transmit a downlink commonchannel, a user equipment terminal in which the time frame to transmitacknowledgement information with respect to the downlink shared channeloverlaps with a time frame to transmit acknowledgement information withrespect to an uplink shared channel, and a user equipment terminal inwhich the time frame to transmit acknowledgement information withrespect to the downlink shared channel overlaps with a time frame totransmit control information for downlink or uplink PersistentScheduling; and a transmission unit configured to transmit the downlinkshared channel to the user equipment terminal selected by the selectionunit.
 8. The base station apparatus according to claim 7, wherein theuser equipment terminal is capable of communicating in Half Duplex mode.9. The base station apparatus according to claim 7, wherein the userequipment terminal has a path loss value equal to or greater than apredetermined threshold value and is capable of communication in FullDuplex mode.
 10. The base station apparatus according to claim 7,wherein the downlink common channel is any of a synchronization channel,a broadcast channel, and a paging channel.
 11. A communication controlmethod for a base station apparatus capable of communicating with a userequipment terminal using a downlink shared channel, the methodcomprising: a first excluding step of excluding a first user equipmentterminal from candidate user equipment terminals transmitting a sharedchannel, in the first user equipment terminal, a time frame to transmitthe shared channel or a time frame to receive acknowledgementinformation with respect to the shared channel overlapping with a timeinterval when cells are measured, the cells operating at a differentfrequency; a second excluding step of excluding a second user equipmentterminal from candidate user equipment terminals transmitting a sharedchannel, the second user equipment terminal being in sleep mode ofdiscontinuous reception mode; a third excluding step of excluding athird user equipment terminal from candidate user equipment terminalstransmitting a shared channel, the third user equipment terminal nothaving received radio quality information; a fourth excluding step ofexcluding a fourth user equipment terminal from candidate user equipmentterminals transmitting a shared channel, the fourth user equipmentterminal having no data to be transmitted; a selection step of selectinga user equipment terminal transmitting a shared channel; and atransmitting step of transmitting a shared channel to the user equipmentterminal selected in the selection step.